215690131 has 4 divisors (see below), whose sum is σ = 221519632. Its totient is φ = 209860632.

The previous prime is 215690129. The next prime is 215690143. The reversal of 215690131 is 131096512.

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

It is a cyclic number.

It is not a de Polignac number, because 215690131 - 2¹ = 215690129 is a prime.

It is a super-2 number, since 2×215690131² = 93044465221594322, which contains 22 as substring.

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 215690131.

It is not an unprimeable number, because it can be changed into a prime (215693131) 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, 2914695 + ... + 2914768.

It is an arithmetic number, because the mean of its divisors is an integer number (55379908).

Almost surely, 2^215690131 is an apocalyptic number.

215690131 is a deficient number, since it is larger than the sum of its proper divisors (5829501).

215690131 is an equidigital number, since it uses as much as digits as its factorization.

215690131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5829500.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 215690131 is about 14686.3927157080. The cubic root of 215690131 is about 599.7129469487.

The spelling of 215690131 in words is "two hundred fifteen million, six hundred ninety thousand, one hundred thirty-one".