1521020225 has 6 divisors (see below), whose sum is σ = 1886065110. Its totient is φ = 1216816160.

The previous prime is 1521020219. The next prime is 1521020227. The reversal of 1521020225 is 5220201251.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 7187761 + 1513832464 = 2681^2 + 38908^2 .

It is not a de Polignac number, because 1521020225 - 2²⁴ = 1504243009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1521020197 and 1521020206.

It is not an unprimeable number, because it can be changed into a prime (1521020227) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 30420380 + ... + 30420429.

It is an arithmetic number, because the mean of its divisors is an integer number (314344185).

Almost surely, 2^1521020225 is an apocalyptic number.

It is an amenable number.

1521020225 is a deficient number, since it is larger than the sum of its proper divisors (365044885).

1521020225 is an equidigital number, since it uses as much as digits as its factorization.

1521020225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60840819 (or 60840814 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 1521020225 is about 39000.2592940098. The cubic root of 1521020225 is about 1150.0366024897.

Adding to 1521020225 its reverse (5220201251), we get a palindrome (6741221476).

The spelling of 1521020225 in words is "one billion, five hundred twenty-one million, twenty thousand, two hundred twenty-five".