133815257 has 2 divisors, whose sum is σ = 133815258. Its totient is φ = 133815256.

The previous prime is 133815223. The next prime is 133815277. The reversal of 133815257 is 752518331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124791241 + 9024016 = 11171^2 + 3004^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-133815257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133815217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66907628 + 66907629.

It is an arithmetic number, because the mean of its divisors is an integer number (66907629).

Almost surely, 2^133815257 is an apocalyptic number.

It is an amenable number.

133815257 is a deficient number, since it is larger than the sum of its proper divisors (1).

133815257 is an equidigital number, since it uses as much as digits as its factorization.

133815257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 35.

The square root of 133815257 is about 11567.8544683100. The cubic root of 133815257 is about 511.4877192683.

The spelling of 133815257 in words is "one hundred thirty-three million, eight hundred fifteen thousand, two hundred fifty-seven".