215670 has 64 divisors (see below), whose sum is σ = 645120. Its totient is φ = 44928.

The previous prime is 215659. The next prime is 215681. The reversal of 215670 is 76512.

215670 = 46² + 47² + ... + 90².

215670 is nontrivially palindromic in base 9.

It is an interprime number because it is at equal distance from previous prime (215659) and next prime (215681).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nialpdrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2691 + ... + 2769.

It is an arithmetic number, because the mean of its divisors is an integer number (10080).

2²¹⁵⁶⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322560).

215670 is an abundant number, since it is smaller than the sum of its proper divisors (429450).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215670 is a wasteful number, since it uses less digits than its factorization.

215670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 215670 is about 464.4028423686. The cubic root of 215670 is about 59.9694288705.

The spelling of 215670 in words is "two hundred fifteen thousand, six hundred seventy".