1251178993 has 2 divisors, whose sum is σ = 1251178994. Its totient is φ = 1251178992.

The previous prime is 1251178979. The next prime is 1251179081. The reversal of 1251178993 is 3998711521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1246654864 + 4524129 = 35308^2 + 2127^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251178993 - 2²⁵ = 1217624561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1251178933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625589496 + 625589497.

It is an arithmetic number, because the mean of its divisors is an integer number (625589497).

Almost surely, 2^1251178993 is an apocalyptic number.

It is an amenable number.

1251178993 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251178993 is an equidigital number, since it uses as much as digits as its factorization.

1251178993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 46.

The square root of 1251178993 is about 35372.0086085029. The cubic root of 1251178993 is about 1077.5559137153. Note that the first 3 decimals are identical.

The spelling of 1251178993 in words is "one billion, two hundred fifty-one million, one hundred seventy-eight thousand, nine hundred ninety-three".