215940979 has 2 divisors, whose sum is σ = 215940980. Its totient is φ = 215940978.

The previous prime is 215940961. The next prime is 215941031. The reversal of 215940979 is 979049512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215940979 - 2¹⁷ = 215809907 is a prime.

It is a super-2 number, since 2×215940979² = 93261012822956882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (215940679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107970489 + 107970490.

It is an arithmetic number, because the mean of its divisors is an integer number (107970490).

Almost surely, 2^215940979 is an apocalyptic number.

215940979 is a deficient number, since it is larger than the sum of its proper divisors (1).

215940979 is an equidigital number, since it uses as much as digits as its factorization.

215940979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 46.

The square root of 215940979 is about 14694.9303843196. The cubic root of 215940979 is about 599.9453459476.

The spelling of 215940979 in words is "two hundred fifteen million, nine hundred forty thousand, nine hundred seventy-nine".