20046656681 has 2 divisors, whose sum is σ = 20046656682. Its totient is φ = 20046656680.

The previous prime is 20046656639. The next prime is 20046656689. The reversal of 20046656681 is 18665664002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17711351056 + 2335305625 = 133084^2 + 48325^2 .

It is a cyclic number.

It is not a de Polignac number, because 20046656681 - 2¹⁴ = 20046640297 is a prime.

It is a super-2 number, since 2×20046656681² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20046656689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10023328340 + 10023328341.

It is an arithmetic number, because the mean of its divisors is an integer number (10023328341).

Almost surely, 2^20046656681 is an apocalyptic number.

It is an amenable number.

20046656681 is a deficient number, since it is larger than the sum of its proper divisors (1).

20046656681 is an equidigital number, since it uses as much as digits as its factorization.

20046656681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 44.

The spelling of 20046656681 in words is "twenty billion, forty-six million, six hundred fifty-six thousand, six hundred eighty-one".