61637515706640 has 40 divisors (see below), whose sum is σ = 191076298691328. Its totient is φ = 16436670855040.

The previous prime is 61637515706621. The next prime is 61637515706651. The reversal of 61637515706640 is 4660751573616.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (57) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 128411490816 + ... + 128411491295.

Almost surely, 2^{61637515706640} is an apocalyptic number.

61637515706640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61637515706640 is an abundant number, since it is smaller than the sum of its proper divisors (129438782984688).

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

61637515706640 is a wasteful number, since it uses less digits than its factorization.

61637515706640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256822982127 (or 256822982121 counting only the distinct ones).

The product of its (nonzero) digits is 19051200, while the sum is 57.

The spelling of 61637515706640 in words is "sixty-one trillion, six hundred thirty-seven billion, five hundred fifteen million, seven hundred six thousand, six hundred forty".