21656226251071 has 2 divisors, whose sum is σ = 21656226251072. Its totient is φ = 21656226251070.

The previous prime is 21656226250979. The next prime is 21656226251081. The reversal of 21656226251071 is 17015262265612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21656226251071 - 2⁹ = 21656226250559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21656226251081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10828113125535 + 10828113125536.

It is an arithmetic number, because the mean of its divisors is an integer number (10828113125536).

Almost surely, 2^{21656226251071} is an apocalyptic number.

21656226251071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21656226251071 is an equidigital number, since it uses as much as digits as its factorization.

21656226251071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 21656226251071 in words is "twenty-one trillion, six hundred fifty-six billion, two hundred twenty-six million, two hundred fifty-one thousand, seventy-one".