215540131 has 4 divisors (see below), whose sum is σ = 215746264. Its totient is φ = 215334000.

The previous prime is 215540069. The next prime is 215540159. The reversal of 215540131 is 131045512.

It is a happy number.

215540131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 215540131 - 2¹⁵ = 215507363 is a prime.

It is a super-2 number, since 2×215540131² = 92915096142994322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215540191) 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, 101490 + ... + 103591.

It is an arithmetic number, because the mean of its divisors is an integer number (53936566).

Almost surely, 2^215540131 is an apocalyptic number.

215540131 is a deficient number, since it is larger than the sum of its proper divisors (206133).

215540131 is a wasteful number, since it uses less digits than its factorization.

215540131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206132.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 215540131 is about 14681.2850595580. The cubic root of 215540131 is about 599.5738928298.

Adding to 215540131 its reverse (131045512), we get a palindrome (346585643).

The spelling of 215540131 in words is "two hundred fifteen million, five hundred forty thousand, one hundred thirty-one".