421631999 has 4 divisors (see below), whose sum is σ = 424952064. Its totient is φ = 418311936.

The previous prime is 421631993. The next prime is 421632017. The reversal of 421631999 is 999136124.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 421631999 - 2²⁴ = 404854783 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 (421631993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1659842 + ... + 1660095.

It is an arithmetic number, because the mean of its divisors is an integer number (106238016).

Almost surely, 2^421631999 is an apocalyptic number.

421631999 is a deficient number, since it is larger than the sum of its proper divisors (3320065).

421631999 is a wasteful number, since it uses less digits than its factorization.

421631999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3320064.

The product of its digits is 104976, while the sum is 44.

The square root of 421631999 is about 20533.6796264089. The cubic root of 421631999 is about 749.8559717503.

The spelling of 421631999 in words is "four hundred twenty-one million, six hundred thirty-one thousand, nine hundred ninety-nine".