251023133 has 4 divisors (see below), whose sum is σ = 257807580. Its totient is φ = 244238688.

The previous prime is 251023109. The next prime is 251023147. The reversal of 251023133 is 331320152.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 236605924 + 14417209 = 15382^2 + 3797^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251023133 is a prime.

It is a super-2 number, since 2×251023133² = 126025226602271378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251023103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3392168 + ... + 3392241.

It is an arithmetic number, because the mean of its divisors is an integer number (64451895).

Almost surely, 2^251023133 is an apocalyptic number.

It is an amenable number.

251023133 is a deficient number, since it is larger than the sum of its proper divisors (6784447).

251023133 is an equidigital number, since it uses as much as digits as its factorization.

251023133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6784446.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 251023133 is about 15843.7095719405. The cubic root of 251023133 is about 630.8187331309.

Adding to 251023133 its reverse (331320152), we get a palindrome (582343285).

The spelling of 251023133 in words is "two hundred fifty-one million, twenty-three thousand, one hundred thirty-three".