61089840 has 480 divisors, whose sum is σ = 267411456. Its totient is φ = 12165120.

The previous prime is 61089829. The next prime is 61089859. The reversal of 61089840 is 4898016.

It is a happy number.

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 = 61089795 and 61089804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1970625 + ... + 1970655.

Almost surely, 2^61089840 is an apocalyptic number.

61089840 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 61089840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133705728).

61089840 is an abundant number, since it is smaller than the sum of its proper divisors (206321616).

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

61089840 is a wasteful number, since it uses less digits than its factorization.

61089840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 61089840 is about 7815.9989764585. The cubic root of 61089840 is about 393.8428775613.

The spelling of 61089840 in words is "sixty-one million, eighty-nine thousand, eight hundred forty".