51615605501 has 4 divisors (see below), whose sum is σ = 51624302400. Its totient is φ = 51606908604.

The previous prime is 51615605491. The next prime is 51615605507. The reversal of 51615605501 is 10550651615.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51615605501 is a prime.

It is a super-2 number, since 2×51615605501² (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 (51615605507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4339541 + ... + 4351418.

It is an arithmetic number, because the mean of its divisors is an integer number (12906075600).

Almost surely, 2^51615605501 is an apocalyptic number.

It is an amenable number.

51615605501 is a deficient number, since it is larger than the sum of its proper divisors (8696899).

51615605501 is an equidigital number, since it uses as much as digits as its factorization.

51615605501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8696898.

The product of its (nonzero) digits is 22500, while the sum is 35.

The spelling of 51615605501 in words is "fifty-one billion, six hundred fifteen million, six hundred five thousand, five hundred one".