215977797 has 24 divisors (see below), whose sum is σ = 372038784. Its totient is φ = 118049184.

The previous prime is 215977793. The next prime is 215977799. The reversal of 215977797 is 797779512.

It is not a de Polignac number, because 215977797 - 2² = 215977793 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215977793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73078 + ... + 75975.

It is an arithmetic number, because the mean of its divisors is an integer number (15501616).

Almost surely, 2^215977797 is an apocalyptic number.

It is an amenable number.

215977797 is a deficient number, since it is larger than the sum of its proper divisors (156060987).

215977797 is a wasteful number, since it uses less digits than its factorization.

215977797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149089 (or 149086 counting only the distinct ones).

The product of its digits is 1944810, while the sum is 54.

The square root of 215977797 is about 14696.1830758874. The cubic root of 215977797 is about 599.9794409622.

The spelling of 215977797 in words is "two hundred fifteen million, nine hundred seventy-seven thousand, seven hundred ninety-seven".