215320999 has 2 divisors, whose sum is σ = 215321000. Its totient is φ = 215320998.

The previous prime is 215320981. The next prime is 215321003. The reversal of 215320999 is 999023512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215320999 - 2¹⁹ = 214796711 is a prime.

It is a super-2 number, since 2×215320999² = 92726265220716002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215320979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107660499 + 107660500.

It is an arithmetic number, because the mean of its divisors is an integer number (107660500).

Almost surely, 2^215320999 is an apocalyptic number.

215320999 is a deficient number, since it is larger than the sum of its proper divisors (1).

215320999 is an equidigital number, since it uses as much as digits as its factorization.

215320999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 215320999 is about 14673.8201910750. The cubic root of 215320999 is about 599.3706354349.

The spelling of 215320999 in words is "two hundred fifteen million, three hundred twenty thousand, nine hundred ninety-nine".