1225521521 has 8 divisors (see below), whose sum is σ = 1401867840. Its totient is φ = 1049493168.

The previous prime is 1225521487. The next prime is 1225521523. The reversal of 1225521521 is 1251255221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1225521521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1225521523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71171 + ... + 86696.

It is an arithmetic number, because the mean of its divisors is an integer number (175233480).

Almost surely, 2^1225521521 is an apocalyptic number.

It is an amenable number.

1225521521 is a deficient number, since it is larger than the sum of its proper divisors (176346319).

1225521521 is a wasteful number, since it uses less digits than its factorization.

1225521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158983.

The product of its digits is 2000, while the sum is 26.

The square root of 1225521521 is about 35007.4495072120. The cubic root of 1225521521 is about 1070.1393014550.

Adding to 1225521521 its reverse (1251255221), we get a palindrome (2476776742).

The spelling of 1225521521 in words is "one billion, two hundred twenty-five million, five hundred twenty-one thousand, five hundred twenty-one".