666125401 has 8 divisors (see below), whose sum is σ = 689132808. Its totient is φ = 643440000.

The previous prime is 666125377. The next prime is 666125419. The reversal of 666125401 is 104521666.

It can be written as a sum of positive squares in 4 ways, for example, as 217533001 + 448592400 = 14749^2 + 21180^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666125401 - 2¹³ = 666117209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666155401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76290 + ... + 84571.

It is an arithmetic number, because the mean of its divisors is an integer number (86141601).

Almost surely, 2^666125401 is an apocalyptic number.

It is an amenable number.

666125401 is a deficient number, since it is larger than the sum of its proper divisors (23007407).

666125401 is a wasteful number, since it uses less digits than its factorization.

666125401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161003.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 666125401 is about 25809.4052817960. The cubic root of 666125401 is about 873.3439811682.

The spelling of 666125401 in words is "six hundred sixty-six million, one hundred twenty-five thousand, four hundred one".