61865904 has 20 divisors (see below), whose sum is σ = 159820376. Its totient is φ = 20621952.

The previous prime is 61865897. The next prime is 61865939. The reversal of 61865904 is 40956816.

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 3 ways as a sum of consecutive naturals, for example, 644389 + ... + 644484.

Almost surely, 2^61865904 is an apocalyptic number.

It is an amenable number.

61865904 is an abundant number, since it is smaller than the sum of its proper divisors (97954472).

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

61865904 is a wasteful number, since it uses less digits than its factorization.

61865904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288884 (or 1288878 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 61865904 is about 7865.4881603115. The cubic root of 61865904 is about 395.5036122977.

It can be divided in two parts, 6186 and 5904, that added together give a triangular number (12090 = T₁₅₅).

The spelling of 61865904 in words is "sixty-one million, eight hundred sixty-five thousand, nine hundred four".