21638456486711 has 2 divisors, whose sum is σ = 21638456486712. Its totient is φ = 21638456486710.

The previous prime is 21638456486627. The next prime is 21638456486719. The reversal of 21638456486711 is 11768465483612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21638456486711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21638456486719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10819228243355 + 10819228243356.

It is an arithmetic number, because the mean of its divisors is an integer number (10819228243356).

Almost surely, 2^{21638456486711} is an apocalyptic number.

21638456486711 is a deficient number, since it is larger than the sum of its proper divisors (1).

21638456486711 is an equidigital number, since it uses as much as digits as its factorization.

21638456486711 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46448640, while the sum is 62.

The spelling of 21638456486711 in words is "twenty-one trillion, six hundred thirty-eight billion, four hundred fifty-six million, four hundred eighty-six thousand, seven hundred eleven".