21320373657601 has 4 divisors (see below), whose sum is σ = 21638588189872. Its totient is φ = 21002159125332.

The previous prime is 21320373657599. The next prime is 21320373657607. The reversal of 21320373657601 is 10675637302312.

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 21320373657601 - 2¹ = 21320373657599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320373657607) 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, 159107266035 + ... + 159107266168.

It is an arithmetic number, because the mean of its divisors is an integer number (5409647047468).

Almost surely, 2^{21320373657601} is an apocalyptic number.

It is an amenable number.

21320373657601 is a deficient number, since it is larger than the sum of its proper divisors (318214532271).

21320373657601 is an equidigital number, since it uses as much as digits as its factorization.

21320373657601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318214532270.

The product of its (nonzero) digits is 952560, while the sum is 46.

The spelling of 21320373657601 in words is "twenty-one trillion, three hundred twenty billion, three hundred seventy-three million, six hundred fifty-seven thousand, six hundred one".