20973109 has 2 divisors, whose sum is σ = 20973110. Its totient is φ = 20973108.

The previous prime is 20973089. The next prime is 20973133. The reversal of 20973109 is 90137902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20884900 + 88209 = 4570^2 + 297^2 .

It is a cyclic number.

It is not a de Polignac number, because 20973109 - 2⁷ = 20972981 is a prime.

It is a super-2 number, since 2×20973109² = 879742602251762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20973179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10486554 + 10486555.

It is an arithmetic number, because the mean of its divisors is an integer number (10486555).

Almost surely, 2^20973109 is an apocalyptic number.

It is an amenable number.

20973109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20973109 is an equidigital number, since it uses as much as digits as its factorization.

20973109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 20973109 is about 4579.6407064310. The cubic root of 20973109 is about 275.7746050666.

The spelling of 20973109 in words is "twenty million, nine hundred seventy-three thousand, one hundred nine".