61787678715 has 64 divisors (see below), whose sum is σ = 128098944000. Its totient is φ = 28245774816.

The previous prime is 61787678681. The next prime is 61787678747. The reversal of 61787678715 is 51787678716.

61787678715 is a `hidden beast` number, since 617 + 8 + 7 + 6 + 7 + 8 + 7 + 1 + 5 = 666.

It is not a de Polignac number, because 61787678715 - 2⁷ = 61787678587 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 620877 + ... + 713486.

It is an arithmetic number, because the mean of its divisors is an integer number (2001546000).

Almost surely, 2^61787678715 is an apocalyptic number.

61787678715 is an abundant number, since it is smaller than the sum of its proper divisors (66311265285).

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

61787678715 is a wasteful number, since it uses less digits than its factorization.

61787678715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1334398 (or 1334378 counting only the distinct ones).

The product of its digits is 27659520, while the sum is 63.

Subtracting from 61787678715 its reverse (51787678716), we obtain a palindrome (9999999999).

The spelling of 61787678715 in words is "sixty-one billion, seven hundred eighty-seven million, six hundred seventy-eight thousand, seven hundred fifteen".