1261613 has 4 divisors (see below), whose sum is σ = 1266780. Its totient is φ = 1256448.

The previous prime is 1261571. The next prime is 1261627. The reversal of 1261613 is 3161621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3161621 = 827 ⋅3823.

It can be written as a sum of positive squares in 2 ways, for example, as 1247689 + 13924 = 1117^2 + 118^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261613 - 2⁶ = 1261549 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 (1261643) 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, 2198 + ... + 2711.

It is an arithmetic number, because the mean of its divisors is an integer number (316695).

2^1261613 is an apocalyptic number.

It is an amenable number.

1261613 is a deficient number, since it is larger than the sum of its proper divisors (5167).

1261613 is an equidigital number, since it uses as much as digits as its factorization.

1261613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5166.

The product of its digits is 216, while the sum is 20.

The square root of 1261613 is about 1123.2154735401. The cubic root of 1261613 is about 108.0542993984.

The spelling of 1261613 in words is "one million, two hundred sixty-one thousand, six hundred thirteen".