20653961 has 2 divisors, whose sum is σ = 20653962. Its totient is φ = 20653960.

The previous prime is 20653957. The next prime is 20653973. The reversal of 20653961 is 16935602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12559936 + 8094025 = 3544^2 + 2845^2 .

It is a cyclic number.

It is not a de Polignac number, because 20653961 - 2² = 20653957 is a prime.

It is a super-2 number, since 2×20653961² = 853172209979042, which contains 22 as substring.

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 (20653901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10326980 + 10326981.

It is an arithmetic number, because the mean of its divisors is an integer number (10326981).

Almost surely, 2^20653961 is an apocalyptic number.

It is an amenable number.

20653961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20653961 is an equidigital number, since it uses as much as digits as its factorization.

20653961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20653961 is about 4544.6629137924. The cubic root of 20653961 is about 274.3686275746.

The spelling of 20653961 in words is "twenty million, six hundred fifty-three thousand, nine hundred sixty-one".