1312515551 has 4 divisors (see below), whose sum is σ = 1313007432. Its totient is φ = 1312023672.

The previous prime is 1312515517. The next prime is 1312515557. The reversal of 1312515551 is 1555152131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1555152131 = 13 ⋅119627087.

It is a cyclic number.

It is not a de Polignac number, because 1312515551 - 2¹⁸ = 1312253407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312515557) 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, 241916 + ... + 247281.

It is an arithmetic number, because the mean of its divisors is an integer number (328251858).

Almost surely, 2^1312515551 is an apocalyptic number.

1312515551 is a deficient number, since it is larger than the sum of its proper divisors (491881).

1312515551 is an equidigital number, since it uses as much as digits as its factorization.

1312515551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491880.

The product of its digits is 3750, while the sum is 29.

The square root of 1312515551 is about 36228.6564890281. The cubic root of 1312515551 is about 1094.8841091392.

Adding to 1312515551 its reverse (1555152131), we get a palindrome (2867667682).

The spelling of 1312515551 in words is "one billion, three hundred twelve million, five hundred fifteen thousand, five hundred fifty-one".