61131563551 has 4 divisors (see below), whose sum is σ = 63103549504. Its totient is φ = 59159577600.

The previous prime is 61131563539. The next prime is 61131563557. The reversal of 61131563551 is 15536513116.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61131563551 - 2³⁵ = 26771825183 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61131563551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61131563557) 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, 985992930 + ... + 985992991.

It is an arithmetic number, because the mean of its divisors is an integer number (15775887376).

Almost surely, 2^61131563551 is an apocalyptic number.

61131563551 is a deficient number, since it is larger than the sum of its proper divisors (1971985953).

61131563551 is a wasteful number, since it uses less digits than its factorization.

61131563551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1971985952.

The product of its digits is 40500, while the sum is 37.

The spelling of 61131563551 in words is "sixty-one billion, one hundred thirty-one million, five hundred sixty-three thousand, five hundred fifty-one".