1956800666 has 4 divisors (see below), whose sum is σ = 2935201002. Its totient is φ = 978400332.

The previous prime is 1956800603. The next prime is 1956800669. The reversal of 1956800666 is 6660086591.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1784640025 + 172160641 = 42245^2 + 13121^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1956800666.

It is not an unprimeable number, because it can be changed into a prime (1956800669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489200165 + ... + 489200168.

Almost surely, 2^1956800666 is an apocalyptic number.

1956800666 is a deficient number, since it is larger than the sum of its proper divisors (978400336).

1956800666 is an equidigital number, since it uses as much as digits as its factorization.

1956800666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978400335.

The product of its (nonzero) digits is 466560, while the sum is 47.

The square root of 1956800666 is about 44235.7396908880. The cubic root of 1956800666 is about 1250.7836506906.

The spelling of 1956800666 in words is "one billion, nine hundred fifty-six million, eight hundred thousand, six hundred sixty-six".