20979001 has 2 divisors, whose sum is σ = 20979002. Its totient is φ = 20979000.

The previous prime is 20978999. The next prime is 20979017. The reversal of 20979001 is 10097902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 2601 = 4580^2 + 51^2 .

It is a cyclic number.

It is not a de Polignac number, because 20979001 - 2¹ = 20978999 is a prime.

Together with 20978999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20977001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489500 + 10489501.

It is an arithmetic number, because the mean of its divisors is an integer number (10489501).

Almost surely, 2^20979001 is an apocalyptic number.

It is an amenable number.

20979001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20979001 is an equidigital number, since it uses as much as digits as its factorization.

20979001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 20979001 is about 4580.2839431633. The cubic root of 20979001 is about 275.8004272093.

The spelling of 20979001 in words is "twenty million, nine hundred seventy-nine thousand, one".