421089209 has 2 divisors, whose sum is σ = 421089210. Its totient is φ = 421089208.

The previous prime is 421089203. The next prime is 421089211. The reversal of 421089209 is 902980124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 363283600 + 57805609 = 19060^2 + 7603^2 .

It is a cyclic number.

It is not a de Polignac number, because 421089209 - 2¹² = 421085113 is a prime.

It is a super-2 number, since 2×421089209² = 354632243872491362, which contains 22 as substring.

Together with 421089211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (421089203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210544604 + 210544605.

It is an arithmetic number, because the mean of its divisors is an integer number (210544605).

Almost surely, 2^421089209 is an apocalyptic number.

It is an amenable number.

421089209 is a deficient number, since it is larger than the sum of its proper divisors (1).

421089209 is an equidigital number, since it uses as much as digits as its factorization.

421089209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 421089209 is about 20520.4583038489. The cubic root of 421089209 is about 749.5340566631.

The spelling of 421089209 in words is "four hundred twenty-one million, eighty-nine thousand, two hundred nine".