1266745221 has 12 divisors (see below), whose sum is σ = 2091135072. Its totient is φ = 723854376.

The previous prime is 1266745199. The next prime is 1266745243. The reversal of 1266745221 is 1225476621.

It is a happy number.

1266745221 is a `hidden beast` number, since 1 + 2 + 66 + 74 + 522 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1266745199) and next prime (1266745243).

It is not a de Polignac number, because 1266745221 - 2¹⁵ = 1266712453 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266745261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10053471 + ... + 10053596.

It is an arithmetic number, because the mean of its divisors is an integer number (174261256).

Almost surely, 2^1266745221 is an apocalyptic number.

It is an amenable number.

1266745221 is a deficient number, since it is larger than the sum of its proper divisors (824389851).

1266745221 is a wasteful number, since it uses less digits than its factorization.

1266745221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20107080 (or 20107077 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 1266745221 is about 35591.3644161052. The cubic root of 1266745221 is about 1082.0062220399.

The spelling of 1266745221 in words is "one billion, two hundred sixty-six million, seven hundred forty-five thousand, two hundred twenty-one".