1251531402313 has 4 divisors (see below), whose sum is σ = 1251561264660. Its totient is φ = 1251501539968.

The previous prime is 1251531402299. The next prime is 1251531402449. The reversal of 1251531402313 is 3132041351521.

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 978532467264 + 272998935049 = 989208^2 + 522493^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251531402313 - 2²⁵ = 1251497847881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1251531403313) 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, 14868220 + ... + 14952157.

It is an arithmetic number, because the mean of its divisors is an integer number (312890316165).

Almost surely, 2^{1251531402313} is an apocalyptic number.

It is an amenable number.

1251531402313 is a deficient number, since it is larger than the sum of its proper divisors (29862347).

1251531402313 is an equidigital number, since it uses as much as digits as its factorization.

1251531402313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29862346.

The product of its (nonzero) digits is 10800, while the sum is 31.

Adding to 1251531402313 its reverse (3132041351521), we get a palindrome (4383572753834).

The spelling of 1251531402313 in words is "one trillion, two hundred fifty-one billion, five hundred thirty-one million, four hundred two thousand, three hundred thirteen".