421397 has 2 divisors, whose sum is σ = 421398. Its totient is φ = 421396.

The previous prime is 421381. The next prime is 421409. The reversal of 421397 is 793124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 421201 + 196 = 649^2 + 14^2 .

It is a cyclic number.

It is not a de Polignac number, because 421397 - 2⁴ = 421381 is a prime.

It is equal to p₃₅₄₉₅ and since 421397 and 35495 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210698 + 210699.

It is an arithmetic number, because the mean of its divisors is an integer number (210699).

2⁴²¹³⁹⁷ is an apocalyptic number.

It is an amenable number.

421397 is a deficient number, since it is larger than the sum of its proper divisors (1).

421397 is an equidigital number, since it uses as much as digits as its factorization.

421397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1512, while the sum is 26.

The square root of 421397 is about 649.1509839783. The cubic root of 421397 is about 74.9716633692.

It can be divided in two parts, 421 and 397, that added together give a palindrome (818).

The spelling of 421397 in words is "four hundred twenty-one thousand, three hundred ninety-seven".