56161621 has 4 divisors (see below), whose sum is σ = 56402892. Its totient is φ = 55920352.

The previous prime is 56161583. The next prime is 56161627. The reversal of 56161621 is 12616165.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18584721 + 37576900 = 4311^2 + 6130^2 .

It is a cyclic number.

It is not a de Polignac number, because 56161621 - 2⁷ = 56161493 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 56161621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56161627) 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, 120286 + ... + 120751.

It is an arithmetic number, because the mean of its divisors is an integer number (14100723).

Almost surely, 2^56161621 is an apocalyptic number.

It is an amenable number.

56161621 is a deficient number, since it is larger than the sum of its proper divisors (241271).

56161621 is a wasteful number, since it uses less digits than its factorization.

56161621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241270.

The product of its digits is 2160, while the sum is 28.

The square root of 56161621 is about 7494.1057505215. The cubic root of 56161621 is about 382.9539423831.

Adding to 56161621 its reverse (12616165), we get a palindrome (68777786).

The spelling of 56161621 in words is "fifty-six million, one hundred sixty-one thousand, six hundred twenty-one".