51615617 has 4 divisors (see below), whose sum is σ = 51630000. Its totient is φ = 51601236.

The previous prime is 51615607. The next prime is 51615643. The reversal of 51615617 is 71651615.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 51615617 - 2⁴ = 51615601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51615607) 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, 3134 + ... + 10632.

It is an arithmetic number, because the mean of its divisors is an integer number (12907500).

Almost surely, 2^51615617 is an apocalyptic number.

It is an amenable number.

51615617 is a deficient number, since it is larger than the sum of its proper divisors (14383).

51615617 is an equidigital number, since it uses as much as digits as its factorization.

51615617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14382.

The product of its digits is 6300, while the sum is 32.

The square root of 51615617 is about 7184.4009492789. The cubic root of 51615617 is about 372.3291518669.

The spelling of 51615617 in words is "fifty-one million, six hundred fifteen thousand, six hundred seventeen".