1266213613 has 4 divisors (see below), whose sum is σ = 1447101280. Its totient is φ = 1085325948.

The previous prime is 1266213587. The next prime is 1266213679. The reversal of 1266213613 is 3163126621.

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: 3163126621 = 2953 ⋅1071157.

It is not a de Polignac number, because 1266213613 - 2⁵ = 1266213581 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 (1266213313) 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, 90443823 + ... + 90443836.

It is an arithmetic number, because the mean of its divisors is an integer number (361775320).

Almost surely, 2^1266213613 is an apocalyptic number.

It is an amenable number.

1266213613 is a deficient number, since it is larger than the sum of its proper divisors (180887667).

1266213613 is an equidigital number, since it uses as much as digits as its factorization.

1266213613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180887666.

The product of its digits is 7776, while the sum is 31.

The square root of 1266213613 is about 35583.8954163256. The cubic root of 1266213613 is about 1081.8548409947.

The spelling of 1266213613 in words is "one billion, two hundred sixty-six million, two hundred thirteen thousand, six hundred thirteen".