251939949 has 16 divisors (see below), whose sum is σ = 356188608. Its totient is φ = 157853952.

The previous prime is 251939929. The next prime is 251939969. The reversal of 251939949 is 949939152.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (251939929) and next prime (251939969).

It is not a de Polignac number, because 251939949 - 2⁵ = 251939917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251939929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36999 + ... + 43275.

It is an arithmetic number, because the mean of its divisors is an integer number (22261788).

Almost surely, 2^251939949 is an apocalyptic number.

It is an amenable number.

251939949 is a deficient number, since it is larger than the sum of its proper divisors (104248659).

251939949 is a wasteful number, since it uses less digits than its factorization.

251939949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7084.

The product of its digits is 787320, while the sum is 51.

The square root of 251939949 is about 15872.6163249793. The cubic root of 251939949 is about 631.5857833313.

The spelling of 251939949 in words is "two hundred fifty-one million, nine hundred thirty-nine thousand, nine hundred forty-nine".