1251457609 has 2 divisors, whose sum is σ = 1251457610. Its totient is φ = 1251457608.

The previous prime is 1251457511. The next prime is 1251457643. The reversal of 1251457609 is 9067541521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 710755600 + 540702009 = 26660^2 + 23253^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251457609 - 2⁷ = 1251457481 is a prime.

It is a super-2 number, since 2×1251457609² = 3132292294247993762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1251455609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625728804 + 625728805.

It is an arithmetic number, because the mean of its divisors is an integer number (625728805).

Almost surely, 2^1251457609 is an apocalyptic number.

It is an amenable number.

1251457609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251457609 is an equidigital number, since it uses as much as digits as its factorization.

1251457609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 40.

The square root of 1251457609 is about 35375.9467576488. The cubic root of 1251457609 is about 1077.6358921565.

The spelling of 1251457609 in words is "one billion, two hundred fifty-one million, four hundred fifty-seven thousand, six hundred nine".