61657961508 has 96 divisors (see below), whose sum is σ = 187800520320. Its totient is φ = 17246977920.

The previous prime is 61657961489. The next prime is 61657961509. The reversal of 61657961508 is 80516975616.

61657961508 is a `hidden beast` number, since 6 + 1 + 6 + 5 + 79 + 61 + 508 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (61657961509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1980735 + ... + 2011622.

It is an arithmetic number, because the mean of its divisors is an integer number (1956255420).

Almost surely, 2^61657961508 is an apocalyptic number.

It is an amenable number.

61657961508 is an abundant number, since it is smaller than the sum of its proper divisors (126142558812).

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

61657961508 is a wasteful number, since it uses less digits than its factorization.

61657961508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3992394 (or 3992386 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

It can be divided in two parts, 61657 and 961508, that added together give a triangular number (1023165 = T₁₄₃₀).

The spelling of 61657961508 in words is "sixty-one billion, six hundred fifty-seven million, nine hundred sixty-one thousand, five hundred eight".