21946404720601 has 3 divisors (see below), whose sum is σ = 21946409405301. Its totient is φ = 21946400035902.

The previous prime is 21946404720533. The next prime is 21946404720607. The reversal of 21946404720601 is 10602740464912.

The square root of 21946404720601 is 4684699.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 21946404720601 - 2⁹ = 21946404720089 is a prime.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21946404720607) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2342350 + ... + 7027048.

It is an arithmetic number, because the mean of its divisors is an integer number (7315469801767).

Almost surely, 2^{21946404720601} is an apocalyptic number.

21946404720601 is the 4684699-th square number.

21946404720601 is the 2342350-th centered octagonal number.

It is an amenable number.

21946404720601 is a deficient number, since it is larger than the sum of its proper divisors (4684700).

21946404720601 is an frugal number, since it uses more digits than its factorization.

21946404720601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9369398 (or 4684699 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 46.

The spelling of 21946404720601 in words is "twenty-one trillion, nine hundred forty-six billion, four hundred four million, seven hundred twenty thousand, six hundred one".