426664721 has 8 divisors (see below), whose sum is σ = 487839744. Its totient is φ = 365545440.

The previous prime is 426664709. The next prime is 426664739. The reversal of 426664721 is 127466624.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-426664721 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (426664751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4016 + ... + 29486.

It is an arithmetic number, because the mean of its divisors is an integer number (60979968).

Almost surely, 2^426664721 is an apocalyptic number.

It is an amenable number.

426664721 is a deficient number, since it is larger than the sum of its proper divisors (61175023).

426664721 is a wasteful number, since it uses less digits than its factorization.

426664721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27871.

The product of its digits is 96768, while the sum is 38.

The square root of 426664721 is about 20655.8640826280. The cubic root of 426664721 is about 752.8276787641.

The spelling of 426664721 in words is "four hundred twenty-six million, six hundred sixty-four thousand, seven hundred twenty-one".