61864920 has 96 divisors (see below), whose sum is σ = 216543600. Its totient is φ = 15227136.

The previous prime is 61864909. The next prime is 61864961. The reversal of 61864920 is 2946816.

61864920 is a `hidden beast` number, since 6 + 1 + 8 + 649 + 2 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1930 + ... + 11289.

Almost surely, 2^61864920 is an apocalyptic number.

61864920 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 61864920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108271800).

61864920 is an abundant number, since it is smaller than the sum of its proper divisors (154678680).

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

61864920 is a wasteful number, since it uses less digits than its factorization.

61864920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13249 (or 13242 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 61864920 is about 7865.4256083190. The cubic root of 61864920 is about 395.5015154097.

The spelling of 61864920 in words is "sixty-one million, eight hundred sixty-four thousand, nine hundred twenty".