126509531 has 2 divisors, whose sum is σ = 126509532. Its totient is φ = 126509530.

The previous prime is 126509521. The next prime is 126509533. The reversal of 126509531 is 135905621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 126509531 - 2²² = 122315227 is a prime.

It is a super-2 number, since 2×126509531² = 32009322867679922, which contains 22 as substring.

Together with 126509533, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_7191185 and since 126509531 and 7191185 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (126509533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63254765 + 63254766.

It is an arithmetic number, because the mean of its divisors is an integer number (63254766).

Almost surely, 2^126509531 is an apocalyptic number.

126509531 is a deficient number, since it is larger than the sum of its proper divisors (1).

126509531 is an equidigital number, since it uses as much as digits as its factorization.

126509531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 126509531 is about 11247.6455758528. The cubic root of 126509531 is about 502.0046599357.

The spelling of 126509531 in words is "one hundred twenty-six million, five hundred nine thousand, five hundred thirty-one".