421731906 has 16 divisors (see below), whose sum is σ = 855344448. Its totient is φ = 138597200.

The previous prime is 421731901. The next prime is 421731907. The reversal of 421731906 is 609137124.

It is not an unprimeable number, because it can be changed into a prime (421731901) 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, 494565 + ... + 495416.

It is an arithmetic number, because the mean of its divisors is an integer number (53459028).

Almost surely, 2^421731906 is an apocalyptic number.

421731906 is an abundant number, since it is smaller than the sum of its proper divisors (433612542).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421731906 is a wasteful number, since it uses less digits than its factorization.

421731906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990057.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 421731906 is about 20536.1122416099. The cubic root of 421731906 is about 749.9151939665.

The spelling of 421731906 in words is "four hundred twenty-one million, seven hundred thirty-one thousand, nine hundred six".