1261612013 has 4 divisors (see below), whose sum is σ = 1269352128. Its totient is φ = 1253871900.

The previous prime is 1261611997. The next prime is 1261612043. The reversal of 1261612013 is 3102161621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3102161621 = 13 ⋅238627817.

It is a cyclic number.

It is not a de Polignac number, because 1261612013 - 2⁴ = 1261611997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261612013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261612043) 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, 3869813 + ... + 3870138.

It is an arithmetic number, because the mean of its divisors is an integer number (317338032).

Almost surely, 2^1261612013 is an apocalyptic number.

It is an amenable number.

1261612013 is a deficient number, since it is larger than the sum of its proper divisors (7740115).

1261612013 is an equidigital number, since it uses as much as digits as its factorization.

1261612013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7740114.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 1261612013 is about 35519.1781014145. The cubic root of 1261612013 is about 1080.5427122033.

Adding to 1261612013 its reverse (3102161621), we get a palindrome (4363773634).

The spelling of 1261612013 in words is "one billion, two hundred sixty-one million, six hundred twelve thousand, thirteen".