1521921225 has 48 divisors (see below), whose sum is σ = 2791607040. Its totient is φ = 725371200.

The previous prime is 1521921221. The next prime is 1521921229. The reversal of 1521921225 is 5221291251.

It is an interprime number because it is at equal distance from previous prime (1521921221) and next prime (1521921229).

It is not a de Polignac number, because 1521921225 - 2² = 1521921221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1521921192 and 1521921201.

It is not an unprimeable number, because it can be changed into a prime (1521921221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 33042 + ... + 64308.

It is an arithmetic number, because the mean of its divisors is an integer number (58158480).

Almost surely, 2^1521921225 is an apocalyptic number.

1521921225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1521921225 is a deficient number, since it is larger than the sum of its proper divisors (1269685815).

1521921225 is a wasteful number, since it uses less digits than its factorization.

1521921225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31350 (or 31345 counting only the distinct ones).

The product of its digits is 3600, while the sum is 30.

The square root of 1521921225 is about 39011.8087891346. The cubic root of 1521921225 is about 1150.2636383589.

The spelling of 1521921225 in words is "one billion, five hundred twenty-one million, nine hundred twenty-one thousand, two hundred twenty-five".