61520431689 has 16 divisors (see below), whose sum is σ = 91253794240. Its totient is φ = 40963034880.

The previous prime is 61520431681. The next prime is 61520431699. The reversal of 61520431689 is 98613402516.

61520431689 is a `hidden beast` number, since 6 + 1 + 520 + 43 + 1 + 6 + 89 = 666.

61520431689 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61520431689 - 2³ = 61520431681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61520431681) 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, 1382872 + ... + 1426665.

It is an arithmetic number, because the mean of its divisors is an integer number (5703362140).

Almost surely, 2^61520431689 is an apocalyptic number.

It is an amenable number.

61520431689 is a deficient number, since it is larger than the sum of its proper divisors (29733362551).

61520431689 is a wasteful number, since it uses less digits than its factorization.

61520431689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2810357 (or 2810351 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 61520431689 in words is "sixty-one billion, five hundred twenty million, four hundred thirty-one thousand, six hundred eighty-nine".