61634020644 has 243 divisors, whose sum is σ = 190195728177. Its totient is φ = 16778539008.

The previous prime is 61634020607. The next prime is 61634020661. The reversal of 61634020644 is 44602043616.

The square root of 61634020644 is 248262.

It is a perfect power (a square), and thus also a powerful number.

61634020644 is a `hidden beast` number, since 6 + 1 + 6 + 3 + 4 + 0 + 2 + 0 + 644 = 666.

It can be written as a sum of positive squares in only one way, i.e., 60678468900 + 955551744 = 246330^2 + 30912^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 61634020599 and 61634020608.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 239820964 + ... + 239821220.

Almost surely, 2^61634020644 is an apocalyptic number.

61634020644 is the 248262-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61634020644

61634020644 is an abundant number, since it is smaller than the sum of its proper divisors (128561707533).

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

61634020644 is a wasteful number, since it uses less digits than its factorization.

61634020644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

Multiplying 61634020644 by its sum of digits (36), we get a square (2218824743184 = 1489572²).

61634020644 divided by its sum of digits (36) gives a square (1712056129 = 41377²).

The spelling of 61634020644 in words is "sixty-one billion, six hundred thirty-four million, twenty thousand, six hundred forty-four".