61533864 has 64 divisors (see below), whose sum is σ = 195350400. Its totient is φ = 17580672.

The previous prime is 61533833. The next prime is 61533869. The reversal of 61533864 is 46833516.

61533864 is a `hidden beast` number, since 61 + 533 + 8 + 64 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (61533869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18837 + ... + 21860.

It is an arithmetic number, because the mean of its divisors is an integer number (3052350).

Almost surely, 2^61533864 is an apocalyptic number.

It is an amenable number.

61533864 is an abundant number, since it is smaller than the sum of its proper divisors (133816536).

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

61533864 is a wasteful number, since it uses less digits than its factorization.

61533864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40719 (or 40709 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 61533864 is about 7844.3523633248. The cubic root of 61533864 is about 394.7947745541.

The spelling of 61533864 in words is "sixty-one million, five hundred thirty-three thousand, eight hundred sixty-four".