215564651 has 2 divisors, whose sum is σ = 215564652. Its totient is φ = 215564650.

The previous prime is 215564647. The next prime is 215564653. The reversal of 215564651 is 156465512.

215564651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215564651 - 2² = 215564647 is a prime.

Together with 215564653, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_11891753 and since 215564651 and 11891753 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (215564653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107782325 + 107782326.

It is an arithmetic number, because the mean of its divisors is an integer number (107782326).

Almost surely, 2^215564651 is an apocalyptic number.

215564651 is a deficient number, since it is larger than the sum of its proper divisors (1).

215564651 is an equidigital number, since it uses as much as digits as its factorization.

215564651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 35.

The square root of 215564651 is about 14682.1201125723. The cubic root of 215564651 is about 599.5966279532.

The spelling of 215564651 in words is "two hundred fifteen million, five hundred sixty-four thousand, six hundred fifty-one".