20915953 has 2 divisors, whose sum is σ = 20915954. Its totient is φ = 20915952.

The previous prime is 20915929. The next prime is 20915957. The reversal of 20915953 is 35951902.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 12769 = 4572^2 + 113^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20915953 is a prime.

It is not a weakly prime, because it can be changed into another prime (20915957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10457976 + 10457977.

It is an arithmetic number, because the mean of its divisors is an integer number (10457977).

Almost surely, 2^20915953 is an apocalyptic number.

It is an amenable number.

20915953 is a deficient number, since it is larger than the sum of its proper divisors (1).

20915953 is an equidigital number, since it uses as much as digits as its factorization.

20915953 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12150, while the sum is 34.

The square root of 20915953 is about 4573.3962216279. The cubic root of 20915953 is about 275.5238631376.

The spelling of 20915953 in words is "twenty million, nine hundred fifteen thousand, nine hundred fifty-three".