215608655 has 4 divisors (see below), whose sum is σ = 258730392. Its totient is φ = 172486920.

The previous prime is 215608643. The next prime is 215608661. The reversal of 215608655 is 556806512.

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

It is not a de Polignac number, because 215608655 - 2¹⁰ = 215607631 is a prime.

It is a super-2 number, since 2×215608655² = 92974184221818050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21560861 + ... + 21560870.

It is an arithmetic number, because the mean of its divisors is an integer number (64682598).

Almost surely, 2^215608655 is an apocalyptic number.

215608655 is a deficient number, since it is larger than the sum of its proper divisors (43121737).

215608655 is an equidigital number, since it uses as much as digits as its factorization.

215608655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43121736.

The product of its (nonzero) digits is 72000, while the sum is 38.

The square root of 215608655 is about 14683.6185935211. The cubic root of 215608655 is about 599.6374244609.

The spelling of 215608655 in words is "two hundred fifteen million, six hundred eight thousand, six hundred fifty-five".