215020531 has 4 divisors (see below), whose sum is σ = 234567864. Its totient is φ = 195473200.

The previous prime is 215020517. The next prime is 215020567. The reversal of 215020531 is 135020512.

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 215020531 - 2⁵ = 215020499 is a prime.

It is a super-2 number, since 2×215020531² = 92467657503043922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 215020499 and 215020508.

It is not an unprimeable number, because it can be changed into a prime (215020591) 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 3 ways as a sum of consecutive naturals, for example, 9773650 + ... + 9773671.

It is an arithmetic number, because the mean of its divisors is an integer number (58641966).

Almost surely, 2^215020531 is an apocalyptic number.

215020531 is a deficient number, since it is larger than the sum of its proper divisors (19547333).

215020531 is a wasteful number, since it uses less digits than its factorization.

215020531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19547332.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 215020531 is about 14663.5783831915. The cubic root of 215020531 is about 599.0917099684.

Subtracting from 215020531 its sum of digits (19), we obtain a palindrome (215020512).

The spelling of 215020531 in words is "two hundred fifteen million, twenty thousand, five hundred thirty-one".