421329991 has 2 divisors, whose sum is σ = 421329992. Its totient is φ = 421329990.

The previous prime is 421329977. The next prime is 421330069. The reversal of 421329991 is 199923124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 421329991 - 2⁷ = 421329863 is a prime.

It is a super-2 number, since 2×421329991² = 355037922632120162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421329911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210664995 + 210664996.

It is an arithmetic number, because the mean of its divisors is an integer number (210664996).

Almost surely, 2^421329991 is an apocalyptic number.

421329991 is a deficient number, since it is larger than the sum of its proper divisors (1).

421329991 is an equidigital number, since it uses as much as digits as its factorization.

421329991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 40.

The square root of 421329991 is about 20526.3243421710. The cubic root of 421329991 is about 749.6768925258.

The spelling of 421329991 in words is "four hundred twenty-one million, three hundred twenty-nine thousand, nine hundred ninety-one".