421991911 has 4 divisors (see below), whose sum is σ = 460354824. Its totient is φ = 383629000.

The previous prime is 421991891. The next prime is 421991939. The reversal of 421991911 is 119199124.

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 421991911 - 2⁹ = 421991399 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 (421991951) 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, 19181440 + ... + 19181461.

It is an arithmetic number, because the mean of its divisors is an integer number (115088706).

Almost surely, 2^421991911 is an apocalyptic number.

421991911 is a deficient number, since it is larger than the sum of its proper divisors (38362913).

421991911 is a wasteful number, since it uses less digits than its factorization.

421991911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38362912.

The product of its digits is 5832, while the sum is 37.

The square root of 421991911 is about 20542.4417000511. The cubic root of 421991911 is about 750.0692741938.

The spelling of 421991911 in words is "four hundred twenty-one million, nine hundred ninety-one thousand, nine hundred eleven".