20972730397 has 2 divisors, whose sum is σ = 20972730398. Its totient is φ = 20972730396.

The previous prime is 20972730377. The next prime is 20972730463. The reversal of 20972730397 is 79303727902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19508826276 + 1463904121 = 139674^2 + 38261^2 .

It is a cyclic number.

It is not a de Polignac number, because 20972730397 - 2⁷ = 20972730269 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20972730397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20972730377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10486365198 + 10486365199.

It is an arithmetic number, because the mean of its divisors is an integer number (10486365199).

Almost surely, 2^20972730397 is an apocalyptic number.

It is an amenable number.

20972730397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20972730397 is an equidigital number, since it uses as much as digits as its factorization.

20972730397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1000188, while the sum is 49.

The spelling of 20972730397 in words is "twenty billion, nine hundred seventy-two million, seven hundred thirty thousand, three hundred ninety-seven".