331729121 has 2 divisors, whose sum is σ = 331729122. Its totient is φ = 331729120.

The previous prime is 331729117. The next prime is 331729169. The reversal of 331729121 is 121927133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 300536896 + 31192225 = 17336^2 + 5585^2 .

It is an emirp because it is prime and its reverse (121927133) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 331729121 - 2² = 331729117 is a prime.

It is a super-2 number, since 2×331729121² = 220088419438865282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (331729421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165864560 + 165864561.

It is an arithmetic number, because the mean of its divisors is an integer number (165864561).

Almost surely, 2^331729121 is an apocalyptic number.

It is an amenable number.

331729121 is a deficient number, since it is larger than the sum of its proper divisors (1).

331729121 is an equidigital number, since it uses as much as digits as its factorization.

331729121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 29.

The square root of 331729121 is about 18213.4324332345. The cubic root of 331729121 is about 692.2471864934.

The spelling of 331729121 in words is "three hundred thirty-one million, seven hundred twenty-nine thousand, one hundred twenty-one".