215501 has 12 divisors (see below), whose sum is σ = 256956. Its totient is φ = 179520.

The previous prime is 215497. The next prime is 215503. The reversal of 215501 is 105512.

It can be written as a sum of positive squares in 2 ways, for example, as 75625 + 139876 = 275^2 + 374^2 .

It is not a de Polignac number, because 215501 - 2² = 215497 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215503) 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, 1505 + ... + 1641.

It is an arithmetic number, because the mean of its divisors is an integer number (21413).

2²¹⁵⁵⁰¹ is an apocalyptic number.

It is an amenable number.

215501 is a deficient number, since it is larger than the sum of its proper divisors (41455).

215501 is a wasteful number, since it uses less digits than its factorization.

215501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 14.

The square root of 215501 is about 464.2208526122. The cubic root of 215501 is about 59.9537606709.

The spelling of 215501 in words is "two hundred fifteen thousand, five hundred one".