1251535091 has 2 divisors, whose sum is σ = 1251535092. Its totient is φ = 1251535090.

The previous prime is 1251535039. The next prime is 1251535123. The reversal of 1251535091 is 1905351521.

It is an a-pointer prime, because the next prime (1251535123) can be obtained adding 1251535091 to its sum of digits (32).

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1251535091 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251535591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625767545 + 625767546.

It is an arithmetic number, because the mean of its divisors is an integer number (625767546).

Almost surely, 2^1251535091 is an apocalyptic number.

1251535091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251535091 is an equidigital number, since it uses as much as digits as its factorization.

1251535091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6750, while the sum is 32.

The square root of 1251535091 is about 35377.0418633328. The cubic root of 1251535091 is about 1077.6581317328.

The spelling of 1251535091 in words is "one billion, two hundred fifty-one million, five hundred thirty-five thousand, ninety-one".