20980957 has 2 divisors, whose sum is σ = 20980958. Its totient is φ = 20980956.

The previous prime is 20980943. The next prime is 20980987. The reversal of 20980957 is 75908902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20557156 + 423801 = 4534^2 + 651^2 .

It is a cyclic number.

It is not a de Polignac number, because 20980957 - 2¹⁵ = 20948189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20980987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10490478 + 10490479.

It is an arithmetic number, because the mean of its divisors is an integer number (10490479).

Almost surely, 2^20980957 is an apocalyptic number.

It is an amenable number.

20980957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20980957 is an equidigital number, since it uses as much as digits as its factorization.

20980957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 20980957 is about 4580.4974620668. The cubic root of 20980957 is about 275.8089984606.

The spelling of 20980957 in words is "twenty million, nine hundred eighty thousand, nine hundred fifty-seven".