1666722825 has 120 divisors (see below), whose sum is σ = 3192611136. Its totient is φ = 859248000.

The previous prime is 1666722817. The next prime is 1666722839. The reversal of 1666722825 is 5282276661.

It is not a de Polignac number, because 1666722825 - 2³ = 1666722817 is a prime.

It is a super-3 number, since 3×1666722825³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 12723010 + ... + 12723140.

Almost surely, 2^1666722825 is an apocalyptic number.

1666722825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666722825 is a deficient number, since it is larger than the sum of its proper divisors (1525888311).

1666722825 is a wasteful number, since it uses less digits than its factorization.

1666722825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 303 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 1666722825 is about 40825.5168368999. The cubic root of 1666722825 is about 1185.6444179604.

The spelling of 1666722825 in words is "one billion, six hundred sixty-six million, seven hundred twenty-two thousand, eight hundred twenty-five".