56215511 has 6 divisors (see below), whose sum is σ = 61790736. Its totient is φ = 51104900.

The previous prime is 56215501. The next prime is 56215513. The reversal of 56215511 is 11551265.

It is a de Polignac number, because none of the positive numbers 2^k-56215511 is a prime.

It is a super-2 number, since 2×56215511² = 6320367353982242, which 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 (56215513) 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 5 ways as a sum of consecutive naturals, for example, 232175 + ... + 232416.

It is an arithmetic number, because the mean of its divisors is an integer number (10298456).

Almost surely, 2^56215511 is an apocalyptic number.

56215511 is a deficient number, since it is larger than the sum of its proper divisors (5575225).

56215511 is a wasteful number, since it uses less digits than its factorization.

56215511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464613 (or 464602 counting only the distinct ones).

The product of its digits is 1500, while the sum is 26.

The square root of 56215511 is about 7497.7003807834. The cubic root of 56215511 is about 383.0763913095.

Adding to 56215511 its reverse (11551265), we get a palindrome (67766776).

The spelling of 56215511 in words is "fifty-six million, two hundred fifteen thousand, five hundred eleven".