251121345 has 16 divisors (see below), whose sum is σ = 402253440. Its totient is φ = 133778304.

The previous prime is 251121319. The next prime is 251121349. The reversal of 251121345 is 543121152.

It is a happy number.

It is not a de Polignac number, because 251121345 - 2⁶ = 251121281 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (251121349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4677 + ... + 22893.

It is an arithmetic number, because the mean of its divisors is an integer number (25140840).

Almost surely, 2^251121345 is an apocalyptic number.

It is an amenable number.

251121345 is a deficient number, since it is larger than the sum of its proper divisors (151132095).

251121345 is a wasteful number, since it uses less digits than its factorization.

251121345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19144.

The product of its digits is 1200, while the sum is 24.

The square root of 251121345 is about 15846.8086692558. The cubic root of 251121345 is about 630.9009910098.

Adding to 251121345 its reverse (543121152), we get a palindrome (794242497).

The spelling of 251121345 in words is "two hundred fifty-one million, one hundred twenty-one thousand, three hundred forty-five".