20931353 has 2 divisors, whose sum is σ = 20931354. Its totient is φ = 20931352.

The previous prime is 20931349. The next prime is 20931367. The reversal of 20931353 is 35313902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14992384 + 5938969 = 3872^2 + 2437^2 .

It is a cyclic number.

It is not a de Polignac number, because 20931353 - 2² = 20931349 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20931373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10465676 + 10465677.

It is an arithmetic number, because the mean of its divisors is an integer number (10465677).

Almost surely, 2^20931353 is an apocalyptic number.

It is an amenable number.

20931353 is a deficient number, since it is larger than the sum of its proper divisors (1).

20931353 is an equidigital number, since it uses as much as digits as its factorization.

20931353 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2430, while the sum is 26.

The square root of 20931353 is about 4575.0795621497. The cubic root of 20931353 is about 275.5914674611.

The spelling of 20931353 in words is "twenty million, nine hundred thirty-one thousand, three hundred fifty-three".