251339989 has 2 divisors, whose sum is σ = 251339990. Its totient is φ = 251339988.

The previous prime is 251339903. The next prime is 251340029. The reversal of 251339989 is 989933152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 250683889 + 656100 = 15833^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 251339989 - 2⁷ = 251339861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251334989) 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, 125669994 + 125669995.

It is an arithmetic number, because the mean of its divisors is an integer number (125669995).

Almost surely, 2^251339989 is an apocalyptic number.

It is an amenable number.

251339989 is a deficient number, since it is larger than the sum of its proper divisors (1).

251339989 is an equidigital number, since it uses as much as digits as its factorization.

251339989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 524880, while the sum is 49.

The square root of 251339989 is about 15853.7058443759. The cubic root of 251339989 is about 631.0840402330.

The spelling of 251339989 in words is "two hundred fifty-one million, three hundred thirty-nine thousand, nine hundred eighty-nine".