61549555728 has 20 divisors (see below), whose sum is σ = 159003019088. Its totient is φ = 20516518560.

The previous prime is 61549555679. The next prime is 61549555729. The reversal of 61549555728 is 82755594516.

It is not an unprimeable number, because it can be changed into a prime (61549555729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 641141158 + ... + 641141253.

Almost surely, 2^61549555728 is an apocalyptic number.

It is an amenable number.

61549555728 is an abundant number, since it is smaller than the sum of its proper divisors (97453463360).

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

61549555728 is a wasteful number, since it uses less digits than its factorization.

61549555728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1282282422 (or 1282282416 counting only the distinct ones).

The product of its digits is 15120000, while the sum is 57.

The spelling of 61549555728 in words is "sixty-one billion, five hundred forty-nine million, five hundred fifty-five thousand, seven hundred twenty-eight".