61039991815 has 16 divisors (see below), whose sum is σ = 79936164000. Its totient is φ = 44376462720.

The previous prime is 61039991813. The next prime is 61039991861. The reversal of 61039991815 is 51819993016.

It is not a de Polignac number, because 61039991815 - 2¹ = 61039991813 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61039991813) 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, 50664 + ... + 353053.

It is an arithmetic number, because the mean of its divisors is an integer number (4996010250).

Almost surely, 2^61039991815 is an apocalyptic number.

61039991815 is a deficient number, since it is larger than the sum of its proper divisors (18896172185).

61039991815 is a wasteful number, since it uses less digits than its factorization.

61039991815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406482.

The product of its (nonzero) digits is 524880, while the sum is 52.

The spelling of 61039991815 in words is "sixty-one billion, thirty-nine million, nine hundred ninety-one thousand, eight hundred fifteen".