21970979 has 8 divisors (see below), whose sum is σ = 22545072. Its totient is φ = 21399840.

The previous prime is 21970969. The next prime is 21970981. The reversal of 21970979 is 97907912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21970979 - 2¹² = 21966883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21970939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28037 + ... + 28809.

It is an arithmetic number, because the mean of its divisors is an integer number (2818134).

Almost surely, 2^21970979 is an apocalyptic number.

21970979 is a deficient number, since it is larger than the sum of its proper divisors (574093).

21970979 is an equidigital number, since it uses as much as digits as its factorization.

21970979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1477.

The product of its (nonzero) digits is 71442, while the sum is 44.

The square root of 21970979 is about 4687.3210899191. The cubic root of 21970979 is about 280.0806697835.

The spelling of 21970979 in words is "twenty-one million, nine hundred seventy thousand, nine hundred seventy-nine".