61683840 has 96 divisors (see below), whose sum is σ = 213021900. Its totient is φ = 16447488.

The previous prime is 61683829. The next prime is 61683883. The reversal of 61683840 is 4838616.

It is a happy number.

61683840 is a `hidden beast` number, since 616 + 8 + 38 + 4 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 58614336 + 3069504 = 7656^2 + 1752^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×61683840² = 7609792234291200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61683795 and 61683804.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 406 + ... + 11114.

Almost surely, 2^61683840 is an apocalyptic number.

61683840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61683840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106510950).

61683840 is an abundant number, since it is smaller than the sum of its proper divisors (151338060).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61683840 is a wasteful number, since it uses less digits than its factorization.

61683840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10734 (or 10719 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 61683840 is about 7853.9060345792. The cubic root of 61683840 is about 395.1152577184.

The spelling of 61683840 in words is "sixty-one million, six hundred eighty-three thousand, eight hundred forty".