1261513031 has 4 divisors (see below), whose sum is σ = 1261695000. Its totient is φ = 1261331064.

The previous prime is 1261513013. The next prime is 1261513063. The reversal of 1261513031 is 1303151621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1303151621 = 11311 ⋅115211.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261513031 is a prime.

It is a super-2 number, since 2×1261513031² = 3182830254765613922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1261512988 and 1261513006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261513091) 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, 80156 + ... + 94593.

It is an arithmetic number, because the mean of its divisors is an integer number (315423750).

Almost surely, 2^1261513031 is an apocalyptic number.

1261513031 is a deficient number, since it is larger than the sum of its proper divisors (181969).

1261513031 is an equidigital number, since it uses as much as digits as its factorization.

1261513031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181968.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 1261513031 is about 35517.7847141400. The cubic root of 1261513031 is about 1080.5144528349.

Adding to 1261513031 its reverse (1303151621), we get a palindrome (2564664652).

The spelling of 1261513031 in words is "one billion, two hundred sixty-one million, five hundred thirteen thousand, thirty-one".