421214921 has 2 divisors, whose sum is σ = 421214922. Its totient is φ = 421214920.

The previous prime is 421214909. The next prime is 421214947. The reversal of 421214921 is 129412124.

It is an a-pointer prime, because the next prime (421214947) can be obtained adding 421214921 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 379470400 + 41744521 = 19480^2 + 6461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421214921 is a prime.

It is a Chen prime.

It is equal to p_22405724 and since 421214921 and 22405724 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (421214951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210607460 + 210607461.

It is an arithmetic number, because the mean of its divisors is an integer number (210607461).

Almost surely, 2^421214921 is an apocalyptic number.

It is an amenable number.

421214921 is a deficient number, since it is larger than the sum of its proper divisors (1).

421214921 is an equidigital number, since it uses as much as digits as its factorization.

421214921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 26.

The square root of 421214921 is about 20523.5211647514. The cubic root of 421214921 is about 749.6086378905.

The spelling of 421214921 in words is "four hundred twenty-one million, two hundred fourteen thousand, nine hundred twenty-one".