421931781 has 32 divisors (see below), whose sum is σ = 651784320. Its totient is φ = 269523072.

The previous prime is 421931767. The next prime is 421931791. The reversal of 421931781 is 187139124.

It is a happy number.

It is not a de Polignac number, because 421931781 - 2⁹ = 421931269 is a prime.

It is a super-2 number, since 2×421931781² = 356052855635663922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421931791) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58105 + ... + 64961.

It is an arithmetic number, because the mean of its divisors is an integer number (20368260).

Almost surely, 2^421931781 is an apocalyptic number.

It is an amenable number.

421931781 is a deficient number, since it is larger than the sum of its proper divisors (229852539).

421931781 is a wasteful number, since it uses less digits than its factorization.

421931781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6962 (or 6956 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 421931781 is about 20540.9780925836. The cubic root of 421931781 is about 750.0336464905.

The spelling of 421931781 in words is "four hundred twenty-one million, nine hundred thirty-one thousand, seven hundred eighty-one".