61555650551 has 32 divisors (see below), whose sum is σ = 64889299200. Its totient is φ = 58342394880.

The previous prime is 61555650511. The next prime is 61555650581. The reversal of 61555650551 is 15505655516.

It is a cyclic number.

It is not a de Polignac number, because 61555650551 - 2³⁰ = 60481908727 is a prime.

It is a super-2 number, since 2×61555650551² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61555650511) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66259655 + ... + 66260583.

It is an arithmetic number, because the mean of its divisors is an integer number (2027790600).

Almost surely, 2^61555650551 is an apocalyptic number.

61555650551 is a deficient number, since it is larger than the sum of its proper divisors (3333648649).

61555650551 is a wasteful number, since it uses less digits than its factorization.

61555650551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1359.

The product of its (nonzero) digits is 562500, while the sum is 44.

The spelling of 61555650551 in words is "sixty-one billion, five hundred fifty-five million, six hundred fifty thousand, five hundred fifty-one".