61557345598464 has 1408 divisors, whose sum is σ = 206052736204800. Its totient is φ = 18062575534080.

The previous prime is 61557345598459. The next prime is 61557345598493. The reversal of 61557345598464 is 46489554375516.

61557345598464 is a `hidden beast` number, since 6 + 1 + 5 + 5 + 7 + 3 + 4 + 559 + 8 + 4 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 61557345598392 and 61557345598401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 62621917717 + ... + 62621918699.

Almost surely, 2^{61557345598464} is an apocalyptic number.

61557345598464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61557345598464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103026368102400).

61557345598464 is an abundant number, since it is smaller than the sum of its proper divisors (144495390606336).

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

61557345598464 is a wasteful number, since it uses less digits than its factorization.

61557345598464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1198 (or 1174 counting only the distinct ones).

The product of its digits is 2177280000, while the sum is 72.

The spelling of 61557345598464 in words is "sixty-one trillion, five hundred fifty-seven billion, three hundred forty-five million, five hundred ninety-eight thousand, four hundred sixty-four".