20362556681 has 2 divisors, whose sum is σ = 20362556682. Its totient is φ = 20362556680.

The previous prime is 20362556639. The next prime is 20362556693. The reversal of 20362556681 is 18665526302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15045230281 + 5317326400 = 122659^2 + 72920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20362556681 is a prime.

It is a super-2 number, since 2×20362556681² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20362558681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10181278340 + 10181278341.

It is an arithmetic number, because the mean of its divisors is an integer number (10181278341).

Almost surely, 2^20362556681 is an apocalyptic number.

It is an amenable number.

20362556681 is a deficient number, since it is larger than the sum of its proper divisors (1).

20362556681 is an equidigital number, since it uses as much as digits as its factorization.

20362556681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 20362556681 in words is "twenty billion, three hundred sixty-two million, five hundred fifty-six thousand, six hundred eighty-one".