213438391 has 2 divisors, whose sum is σ = 213438392. Its totient is φ = 213438390.

The previous prime is 213438361. The next prime is 213438397. The reversal of 213438391 is 193834312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 213438391 - 2⁷ = 213438263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213438397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106719195 + 106719196.

It is an arithmetic number, because the mean of its divisors is an integer number (106719196).

Almost surely, 2^213438391 is an apocalyptic number.

213438391 is a deficient number, since it is larger than the sum of its proper divisors (1).

213438391 is an equidigital number, since it uses as much as digits as its factorization.

213438391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 34.

The square root of 213438391 is about 14609.5308275112. The cubic root of 213438391 is about 597.6187013458.

The spelling of 213438391 in words is "two hundred thirteen million, four hundred thirty-eight thousand, three hundred ninety-one".