666195400 has 96 divisors (see below), whose sum is σ = 1676220840. Its totient is φ = 244776960.

The previous prime is 666195377. The next prime is 666195401. The reversal of 666195400 is 4591666.

It can be written as a sum of positive squares in 12 ways, for example, as 204547204 + 461648196 = 14302^2 + 21486^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 666195400.

It is not an unprimeable number, because it can be changed into a prime (666195401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 667702 + ... + 668698.

Almost surely, 2^666195400 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666195400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (838110420).

666195400 is an abundant number, since it is smaller than the sum of its proper divisors (1010025440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666195400 is a wasteful number, since it uses less digits than its factorization.

666195400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1283 (or 1274 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 666195400 is about 25810.7613215883. The cubic root of 666195400 is about 873.3745715365.

The spelling of 666195400 in words is "six hundred sixty-six million, one hundred ninety-five thousand, four hundred".