213231397 has 2 divisors, whose sum is σ = 213231398. Its totient is φ = 213231396.

The previous prime is 213231379. The next prime is 213231427. The reversal of 213231397 is 793132312.

It is a happy number.

Together with previous prime (213231379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212401476 + 829921 = 14574^2 + 911^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213231397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213231097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106615698 + 106615699.

It is an arithmetic number, because the mean of its divisors is an integer number (106615699).

Almost surely, 2^213231397 is an apocalyptic number.

It is an amenable number.

213231397 is a deficient number, since it is larger than the sum of its proper divisors (1).

213231397 is an equidigital number, since it uses as much as digits as its factorization.

213231397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6804, while the sum is 31.

The square root of 213231397 is about 14602.4448980299. Note that the first 3 decimals coincide. The cubic root of 213231397 is about 597.4254473019.

The spelling of 213231397 in words is "two hundred thirteen million, two hundred thirty-one thousand, three hundred ninety-seven".