1666961125 has 8 divisors (see below), whose sum is σ = 2080367640. Its totient is φ = 1333568800.

The previous prime is 1666961123. The next prime is 1666961137. The reversal of 1666961125 is 5211696661.

It can be written as a sum of positive squares in 4 ways, for example, as 458216836 + 1208744289 = 21406^2 + 34767^2 .

It is not a de Polignac number, because 1666961125 - 2¹ = 1666961123 is a prime.

It is a super-2 number, since 2×1666961125² = 5557518784522531250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666961123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6667720 + ... + 6667969.

It is an arithmetic number, because the mean of its divisors is an integer number (260045955).

Almost surely, 2^1666961125 is an apocalyptic number.

It is an amenable number.

1666961125 is a deficient number, since it is larger than the sum of its proper divisors (413406515).

1666961125 is an equidigital number, since it uses as much as digits as its factorization.

1666961125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13335704 (or 13335694 counting only the distinct ones).

The product of its digits is 116640, while the sum is 43.

The square root of 1666961125 is about 40828.4352504477. The cubic root of 1666961125 is about 1185.7009211767.

The spelling of 1666961125 in words is "one billion, six hundred sixty-six million, nine hundred sixty-one thousand, one hundred twenty-five".