61506055551 has 16 divisors (see below), whose sum is σ = 82785903200. Its totient is φ = 40615354368.

The previous prime is 61506055549. The next prime is 61506055627. The reversal of 61506055551 is 15555060516.

It is not a de Polignac number, because 61506055551 - 2¹ = 61506055549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61506057551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1103235 + ... + 1157643.

It is an arithmetic number, because the mean of its divisors is an integer number (5174118950).

Almost surely, 2^61506055551 is an apocalyptic number.

61506055551 is a deficient number, since it is larger than the sum of its proper divisors (21279847649).

61506055551 is a wasteful number, since it uses less digits than its factorization.

61506055551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57978.

The product of its (nonzero) digits is 112500, while the sum is 39.

The spelling of 61506055551 in words is "sixty-one billion, five hundred six million, fifty-five thousand, five hundred fifty-one".