215923973 has 4 divisors (see below), whose sum is σ = 216215328. Its totient is φ = 215632620.

The previous prime is 215923949. The next prime is 215923979. The reversal of 215923973 is 379329512.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 215923973 - 2⁶ = 215923909 is a prime.

It is a super-2 number, since 2×215923973² = 93246324232209458, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215923973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215923979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144563 + ... + 146048.

It is an arithmetic number, because the mean of its divisors is an integer number (54053832).

Almost surely, 2^215923973 is an apocalyptic number.

It is an amenable number.

215923973 is a deficient number, since it is larger than the sum of its proper divisors (291355).

215923973 is an equidigital number, since it uses as much as digits as its factorization.

215923973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291354.

The product of its digits is 102060, while the sum is 41.

The square root of 215923973 is about 14694.3517379978. The cubic root of 215923973 is about 599.9295963688.

The spelling of 215923973 in words is "two hundred fifteen million, nine hundred twenty-three thousand, nine hundred seventy-three".