215501231 has 12 divisors (see below), whose sum is σ = 249738360. Its totient is φ = 184383360.

The previous prime is 215501213. The next prime is 215501239. The reversal of 215501231 is 132105512.

It is a happy number.

It is not a de Polignac number, because 215501231 - 2¹⁴ = 215484847 is a prime.

It is a super-2 number, since 2×215501231² = 92881561125030722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215501239) 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, 30716 + ... + 37073.

It is an arithmetic number, because the mean of its divisors is an integer number (20811530).

Almost surely, 2^215501231 is an apocalyptic number.

215501231 is a deficient number, since it is larger than the sum of its proper divisors (34237129).

215501231 is a wasteful number, since it uses less digits than its factorization.

215501231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67834 (or 67817 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 215501231 is about 14679.9601838697. The cubic root of 215501231 is about 599.5378209274.

Adding to 215501231 its reverse (132105512), we get a palindrome (347606743).

The spelling of 215501231 in words is "two hundred fifteen million, five hundred one thousand, two hundred thirty-one".