20972641 has 2 divisors, whose sum is σ = 20972642. Its totient is φ = 20972640.

The previous prime is 20972639. The next prime is 20972659. The reversal of 20972641 is 14627902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13838400 + 7134241 = 3720^2 + 2671^2 .

It is a cyclic number.

It is not a de Polignac number, because 20972641 - 2¹ = 20972639 is a prime.

Together with 20972639, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20972621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10486320 + 10486321.

It is an arithmetic number, because the mean of its divisors is an integer number (10486321).

Almost surely, 2^20972641 is an apocalyptic number.

It is an amenable number.

20972641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20972641 is an equidigital number, since it uses as much as digits as its factorization.

20972641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20972641 is about 4579.5896104345. The cubic root of 20972641 is about 275.7725538134.

The spelling of 20972641 in words is "twenty million, nine hundred seventy-two thousand, six hundred forty-one".