61657244544 has 256 divisors, whose sum is σ = 193864366080. Its totient is φ = 16996718592.

The previous prime is 61657244533. The next prime is 61657244557. The reversal of 61657244544 is 44544275616.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 61657244493 and 61657244502.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 9590259 + ... + 9596685.

It is an arithmetic number, because the mean of its divisors is an integer number (757282680).

Almost surely, 2^61657244544 is an apocalyptic number.

61657244544 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 61657244544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96932183040).

61657244544 is an abundant number, since it is smaller than the sum of its proper divisors (132207121536).

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

61657244544 is a wasteful number, since it uses less digits than its factorization.

61657244544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6577 (or 6565 counting only the distinct ones).

The product of its digits is 3225600, while the sum is 48.

The spelling of 61657244544 in words is "sixty-one billion, six hundred fifty-seven million, two hundred forty-four thousand, five hundred forty-four".