1265225621 has 4 divisors (see below), whose sum is σ = 1380246144. Its totient is φ = 1150205100.

The previous prime is 1265225617. The next prime is 1265225627.

1265225621 is nontrivially palindromic in base 10.

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 not a de Polignac number, because 1265225621 - 2² = 1265225617 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 (1265225627) 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, 57510245 + ... + 57510266.

It is an arithmetic number, because the mean of its divisors is an integer number (345061536).

Almost surely, 2^1265225621 is an apocalyptic number.

1265225621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1265225621 is a deficient number, since it is larger than the sum of its proper divisors (115020523).

1265225621 is a wasteful number, since it uses less digits than its factorization.

1265225621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115020522.

The product of its digits is 14400, while the sum is 32.

The square root of 1265225621 is about 35570.0101349437. The cubic root of 1265225621 is about 1081.5733871549.

The spelling of 1265225621 in words is "one billion, two hundred sixty-five million, two hundred twenty-five thousand, six hundred twenty-one".