1521021320225 has 24 divisors (see below), whose sum is σ = 2082316535712. Its totient is φ = 1092869628800.

The previous prime is 1521021320213. The next prime is 1521021320233. The reversal of 1521021320225 is 5220231201251.

It is a happy number.

It is not a de Polignac number, because 1521021320225 - 2⁴ = 1521021320209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1521021320194 and 1521021320203.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33296372 + ... + 33342021.

It is an arithmetic number, because the mean of its divisors is an integer number (86763188988).

Almost surely, 2^{1521021320225} is an apocalyptic number.

It is an amenable number.

1521021320225 is a deficient number, since it is larger than the sum of its proper divisors (561295215487).

1521021320225 is a wasteful number, since it uses less digits than its factorization.

1521021320225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66638497 (or 66638492 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 1521021320225 its reverse (5220231201251), we get a palindrome (6741252521476).

The spelling of 1521021320225 in words is "one trillion, five hundred twenty-one billion, twenty-one million, three hundred twenty thousand, two hundred twenty-five".