215226661 has 16 divisors (see below), whose sum is σ = 252403200. Its totient is φ = 181718208.

The previous prime is 215226643. The next prime is 215226679. The reversal of 215226661 is 166622512.

It is an interprime number because it is at equal distance from previous prime (215226643) and next prime (215226679).

It is a cyclic number.

It is not a de Polignac number, because 215226661 - 2⁵ = 215226629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215226161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7861 + ... + 22186.

It is an arithmetic number, because the mean of its divisors is an integer number (15775200).

Almost surely, 2^215226661 is an apocalyptic number.

It is an amenable number.

215226661 is a deficient number, since it is larger than the sum of its proper divisors (37176539).

215226661 is a wasteful number, since it uses less digits than its factorization.

215226661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30108.

The product of its digits is 8640, while the sum is 31.

The square root of 215226661 is about 14670.6053385673. The cubic root of 215226661 is about 599.2830891095.

The spelling of 215226661 in words is "two hundred fifteen million, two hundred twenty-six thousand, six hundred sixty-one".