21653804701 has 4 divisors (see below), whose sum is σ = 22020818400. Its totient is φ = 21286791004.

The previous prime is 21653804617. The next prime is 21653804707. The reversal of 21653804701 is 10740835612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21653804701 - 2⁹ = 21653804189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21653804707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183506761 + ... + 183506878.

It is an arithmetic number, because the mean of its divisors is an integer number (5505204600).

Almost surely, 2^21653804701 is an apocalyptic number.

It is an amenable number.

21653804701 is a deficient number, since it is larger than the sum of its proper divisors (367013699).

21653804701 is an equidigital number, since it uses as much as digits as its factorization.

21653804701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367013698.

The product of its (nonzero) digits is 40320, while the sum is 37.

The spelling of 21653804701 in words is "twenty-one billion, six hundred fifty-three million, eight hundred four thousand, seven hundred one".