1265221533 has 16 divisors (see below), whose sum is σ = 1792049600. Its totient is φ = 791752320.

The previous prime is 1265221493. The next prime is 1265221543. The reversal of 1265221533 is 3351225621.

It is not a de Polignac number, because 1265221533 - 2⁹ = 1265221021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1265221533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1265221543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95608 + ... + 108033.

It is an arithmetic number, because the mean of its divisors is an integer number (112003100).

Almost surely, 2^1265221533 is an apocalyptic number.

It is an amenable number.

1265221533 is a deficient number, since it is larger than the sum of its proper divisors (526828067).

1265221533 is a wasteful number, since it uses less digits than its factorization.

1265221533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203772.

The product of its digits is 10800, while the sum is 30.

The square root of 1265221533 is about 35569.9526707585. The cubic root of 1265221533 is about 1081.5722222831.

The spelling of 1265221533 in words is "one billion, two hundred sixty-five million, two hundred twenty-one thousand, five hundred thirty-three".