1021660225 has 12 divisors (see below), whose sum is σ = 1288332720. Its totient is φ = 803474000.

The previous prime is 1021660217. The next prime is 1021660247. The reversal of 1021660225 is 5220661201.

It is not a de Polignac number, because 1021660225 - 2³ = 1021660217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 1021660225.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 344851 + ... + 347800.

It is an arithmetic number, because the mean of its divisors is an integer number (107361060).

Almost surely, 2^1021660225 is an apocalyptic number.

It is an amenable number.

1021660225 is a deficient number, since it is larger than the sum of its proper divisors (266672495).

1021660225 is an equidigital number, since it uses as much as digits as its factorization.

1021660225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 692720 (or 692715 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1021660225 is about 31963.4201079922. The cubic root of 1021660225 is about 1007.1685638982.

The spelling of 1021660225 in words is "one billion, twenty-one million, six hundred sixty thousand, two hundred twenty-five".