20556390016739 has 2 divisors, whose sum is σ = 20556390016740. Its totient is φ = 20556390016738.

The previous prime is 20556390016693. The next prime is 20556390016823. The reversal of 20556390016739 is 93761009365502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20556390016739 - 2⁸ = 20556390016483 is a prime.

It is not a weakly prime, because it can be changed into another prime (20556390016039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10278195008369 + 10278195008370.

It is an arithmetic number, because the mean of its divisors is an integer number (10278195008370).

Almost surely, 2^{20556390016739} is an apocalyptic number.

20556390016739 is a deficient number, since it is larger than the sum of its proper divisors (1).

20556390016739 is an equidigital number, since it uses as much as digits as its factorization.

20556390016739 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9185400, while the sum is 56.

The spelling of 20556390016739 in words is "twenty trillion, five hundred fifty-six billion, three hundred ninety million, sixteen thousand, seven hundred thirty-nine".