61275136644 has 36 divisors (see below), whose sum is σ = 154971324144. Its totient is φ = 20414312112.

The previous prime is 61275136613. The next prime is 61275136669. The reversal of 61275136644 is 44663157216.

61275136644 is a `hidden beast` number, since 6 + 127 + 513 + 6 + 6 + 4 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 61275136644.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 377622 + ... + 514925.

It is an arithmetic number, because the mean of its divisors is an integer number (4304759004).

Almost surely, 2^61275136644 is an apocalyptic number.

It is an amenable number.

61275136644 is an abundant number, since it is smaller than the sum of its proper divisors (93696187500).

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

61275136644 is a wasteful number, since it uses less digits than its factorization.

61275136644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894464 (or 894459 counting only the distinct ones).

The product of its digits is 725760, while the sum is 45.

The spelling of 61275136644 in words is "sixty-one billion, two hundred seventy-five million, one hundred thirty-six thousand, six hundred forty-four".