421638393 has 8 divisors (see below), whose sum is σ = 613292256. Its totient is φ = 255538400.

The previous prime is 421638377. The next prime is 421638397. The reversal of 421638393 is 393836124.

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

It is a cyclic number.

It is not a de Polignac number, because 421638393 - 2⁴ = 421638377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (421638397) 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, 6388428 + ... + 6388493.

It is an arithmetic number, because the mean of its divisors is an integer number (76661532).

Almost surely, 2^421638393 is an apocalyptic number.

It is an amenable number.

421638393 is a deficient number, since it is larger than the sum of its proper divisors (191653863).

421638393 is a wasteful number, since it uses less digits than its factorization.

421638393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12776935.

The product of its digits is 93312, while the sum is 39.

The square root of 421638393 is about 20533.8353212448. The cubic root of 421638393 is about 749.8597622239.

The spelling of 421638393 in words is "four hundred twenty-one million, six hundred thirty-eight thousand, three hundred ninety-three".