215020251 has 12 divisors (see below), whose sum is σ = 322088312. Its totient is φ = 143346672.

The previous prime is 215020241. The next prime is 215020279. The reversal of 215020251 is 152020512.

It is not a de Polignac number, because 215020251 - 2⁶ = 215020187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215020231) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 442186 + ... + 442671.

Almost surely, 2^215020251 is an apocalyptic number.

215020251 is a deficient number, since it is larger than the sum of its proper divisors (107068061).

215020251 is an frugal number, since it uses more digits than its factorization.

215020251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884872 (or 884860 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 215020251 is about 14663.5688357235. The cubic root of 215020251 is about 599.0914499223.

Adding to 215020251 its reverse (152020512), we get a palindrome (367040763).

The spelling of 215020251 in words is "two hundred fifteen million, twenty thousand, two hundred fifty-one".