21651767411705 has 32 divisors (see below), whose sum is σ = 27199648005120. Its totient is φ = 16525739888640.

The previous prime is 21651767411683. The next prime is 21651767411749. The reversal of 21651767411705 is 50711476715612.

It is a happy number.

It is not a de Polignac number, because 21651767411705 - 2⁶ = 21651767411641 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25298066 + ... + 26139924.

It is an arithmetic number, because the mean of its divisors is an integer number (849989000160).

Almost surely, 2^{21651767411705} is an apocalyptic number.

It is an amenable number.

21651767411705 is a deficient number, since it is larger than the sum of its proper divisors (5547880593415).

21651767411705 is a wasteful number, since it uses less digits than its factorization.

21651767411705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844241.

The product of its (nonzero) digits is 2469600, while the sum is 53.

The spelling of 21651767411705 in words is "twenty-one trillion, six hundred fifty-one billion, seven hundred sixty-seven million, four hundred eleven thousand, seven hundred five".