21976117 has 4 divisors (see below), whose sum is σ = 22685056. Its totient is φ = 21267180.

The previous prime is 21976111. The next prime is 21976153. The reversal of 21976117 is 71167912.

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 a de Polignac number, because none of the positive numbers 2^k-21976117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21976111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 354423 + ... + 354484.

It is an arithmetic number, because the mean of its divisors is an integer number (5671264).

Almost surely, 2^21976117 is an apocalyptic number.

It is an amenable number.

21976117 is a deficient number, since it is larger than the sum of its proper divisors (708939).

21976117 is an equidigital number, since it uses as much as digits as its factorization.

21976117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708938.

The product of its digits is 5292, while the sum is 34.

The square root of 21976117 is about 4687.8691321324. The cubic root of 21976117 is about 280.1025007379.

The spelling of 21976117 in words is "twenty-one million, nine hundred seventy-six thousand, one hundred seventeen".