20957663 has 2 divisors, whose sum is σ = 20957664. Its totient is φ = 20957662.

The previous prime is 20957659. The next prime is 20957689. The reversal of 20957663 is 36675902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20957663 - 2² = 20957659 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20957603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10478831 + 10478832.

It is an arithmetic number, because the mean of its divisors is an integer number (10478832).

Almost surely, 2^20957663 is an apocalyptic number.

20957663 is a deficient number, since it is larger than the sum of its proper divisors (1).

20957663 is an equidigital number, since it uses as much as digits as its factorization.

20957663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68040, while the sum is 38.

The square root of 20957663 is about 4577.9540189915. The cubic root of 20957663 is about 275.7068888200.

The spelling of 20957663 in words is "twenty million, nine hundred fifty-seven thousand, six hundred sixty-three".