1551315613 has 4 divisors (see below), whose sum is σ = 1593243100. Its totient is φ = 1509388128.

The previous prime is 1551315593. The next prime is 1551315643. The reversal of 1551315613 is 3165131551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3165131551 = 499 ⋅6342949.

It can be written as a sum of positive squares in 2 ways, for example, as 936176409 + 615139204 = 30597^2 + 24802^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551315613 is a prime.

It is a super-2 number, since 2×1551315613² = 4813160262275131538, 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 (1551315643) 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, 20963688 + ... + 20963761.

It is an arithmetic number, because the mean of its divisors is an integer number (398310775).

Almost surely, 2^1551315613 is an apocalyptic number.

It is an amenable number.

1551315613 is a deficient number, since it is larger than the sum of its proper divisors (41927487).

1551315613 is an equidigital number, since it uses as much as digits as its factorization.

1551315613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41927486.

The product of its digits is 6750, while the sum is 31.

The square root of 1551315613 is about 39386.7441279423. The cubic root of 1551315613 is about 1157.6218651460.

The spelling of 1551315613 in words is "one billion, five hundred fifty-one million, three hundred fifteen thousand, six hundred thirteen".