426660021 has 16 divisors (see below), whose sum is σ = 632860800. Its totient is φ = 284092704.

The previous prime is 426660007. The next prime is 426660041. The reversal of 426660021 is 120066624.

It is a happy number.

It is not a de Polignac number, because 426660021 - 2⁶ = 426659957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (426660001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13920 + ... + 32358.

It is an arithmetic number, because the mean of its divisors is an integer number (39553800).

Almost surely, 2^426660021 is an apocalyptic number.

It is an amenable number.

426660021 is a deficient number, since it is larger than the sum of its proper divisors (206200779).

426660021 is a wasteful number, since it uses less digits than its factorization.

426660021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19305 (or 19299 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 426660021 is about 20655.7503131695. The cubic root of 426660021 is about 752.8249144522.

The spelling of 426660021 in words is "four hundred twenty-six million, six hundred sixty thousand, twenty-one".