213791381 has 2 divisors, whose sum is σ = 213791382. Its totient is φ = 213791380.

The previous prime is 213791351. The next prime is 213791429. The reversal of 213791381 is 183197312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212722225 + 1069156 = 14585^2 + 1034^2 .

It is a cyclic number.

It is not a de Polignac number, because 213791381 - 2¹⁸ = 213529237 is a prime.

It is a super-2 number, since 2×213791381² = 91413509179774322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213791351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106895690 + 106895691.

It is an arithmetic number, because the mean of its divisors is an integer number (106895691).

Almost surely, 2^213791381 is an apocalyptic number.

It is an amenable number.

213791381 is a deficient number, since it is larger than the sum of its proper divisors (1).

213791381 is an equidigital number, since it uses as much as digits as its factorization.

213791381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 35.

The square root of 213791381 is about 14621.6066490656. The cubic root of 213791381 is about 597.9479723791.

The spelling of 213791381 in words is "two hundred thirteen million, seven hundred ninety-one thousand, three hundred eighty-one".