21558012727663 has 2 divisors, whose sum is σ = 21558012727664. Its totient is φ = 21558012727662.

The previous prime is 21558012727651. The next prime is 21558012727697. The reversal of 21558012727663 is 36672721085512.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21558012727663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21558012727063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10779006363831 + 10779006363832.

It is an arithmetic number, because the mean of its divisors is an integer number (10779006363832).

Almost surely, 2^{21558012727663} is an apocalyptic number.

21558012727663 is a deficient number, since it is larger than the sum of its proper divisors (1).

21558012727663 is an equidigital number, since it uses as much as digits as its factorization.

21558012727663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8467200, while the sum is 55.

The spelling of 21558012727663 in words is "twenty-one trillion, five hundred fifty-eight billion, twelve million, seven hundred twenty-seven thousand, six hundred sixty-three".