1265422621 has 4 divisors (see below), whose sum is σ = 1265742432. Its totient is φ = 1265102812.

The previous prime is 1265422603. The next prime is 1265422633. The reversal of 1265422621 is 1262245621.

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.

It is a cyclic number.

It is not a de Polignac number, because 1265422621 - 2¹⁷ = 1265291549 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265422601) 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, 153895 + ... + 161908.

It is an arithmetic number, because the mean of its divisors is an integer number (316435608).

Almost surely, 2^1265422621 is an apocalyptic number.

It is an amenable number.

1265422621 is a deficient number, since it is larger than the sum of its proper divisors (319811).

1265422621 is an equidigital number, since it uses as much as digits as its factorization.

1265422621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319810.

The product of its digits is 11520, while the sum is 31.

The square root of 1265422621 is about 35572.7792138877. The cubic root of 1265422621 is about 1081.6295191459.

The spelling of 1265422621 in words is "one billion, two hundred sixty-five million, four hundred twenty-two thousand, six hundred twenty-one".