20627816861 has 2 divisors, whose sum is σ = 20627816862. Its totient is φ = 20627816860.

The previous prime is 20627816827. The next prime is 20627816873. The reversal of 20627816861 is 16861872602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11579051236 + 9048765625 = 107606^2 + 95125^2 .

It is a cyclic number.

It is not a de Polignac number, because 20627816861 - 2³⁴ = 3447947677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20627816161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10313908430 + 10313908431.

It is an arithmetic number, because the mean of its divisors is an integer number (10313908431).

Almost surely, 2^20627816861 is an apocalyptic number.

It is an amenable number.

20627816861 is a deficient number, since it is larger than the sum of its proper divisors (1).

20627816861 is an equidigital number, since it uses as much as digits as its factorization.

20627816861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 47.

The spelling of 20627816861 in words is "twenty billion, six hundred twenty-seven million, eight hundred sixteen thousand, eight hundred sixty-one".