421668013 has 8 divisors (see below), whose sum is σ = 456793400. Its totient is φ = 389229984.

The previous prime is 421668001. The next prime is 421668029. The reversal of 421668013 is 310866124.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 39778249 + 381889764 = 6307^2 + 19542^2 .

It is a de Polignac number, because none of the positive numbers 2^k-421668013 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 (421668043) 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, 93768 + ... + 98161.

It is an arithmetic number, because the mean of its divisors is an integer number (57099175).

Almost surely, 2^421668013 is an apocalyptic number.

It is an amenable number.

421668013 is a deficient number, since it is larger than the sum of its proper divisors (35125387).

421668013 is an equidigital number, since it uses as much as digits as its factorization.

421668013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191968 (or 191942 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 421668013 is about 20534.5565571794. The cubic root of 421668013 is about 749.8773209713.

The spelling of 421668013 in words is "four hundred twenty-one million, six hundred sixty-eight thousand, thirteen".