231221383 has 2 divisors, whose sum is σ = 231221384. Its totient is φ = 231221382.

The previous prime is 231221381. The next prime is 231221401. The reversal of 231221383 is 383122132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231221383 - 2¹ = 231221381 is a prime.

Together with 231221381, it forms a pair of twin primes.

It is equal to p_12706090 and since 231221383 and 12706090 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 (231221381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115610691 + 115610692.

It is an arithmetic number, because the mean of its divisors is an integer number (115610692).

Almost surely, 2^231221383 is an apocalyptic number.

231221383 is a deficient number, since it is larger than the sum of its proper divisors (1).

231221383 is an equidigital number, since it uses as much as digits as its factorization.

231221383 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 25.

The square root of 231221383 is about 15205.9653754702. The cubic root of 231221383 is about 613.7751929463.

The spelling of 231221383 in words is "two hundred thirty-one million, two hundred twenty-one thousand, three hundred eighty-three".