1966994891 has 8 divisors (see below), whose sum is σ = 2053109760. Its totient is φ = 1880929512.

The previous prime is 1966994879. The next prime is 1966994917. The reversal of 1966994891 is 1984996691.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-1966994891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1966994801) 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, 85376 + ... + 105938.

It is an arithmetic number, because the mean of its divisors is an integer number (256638720).

Almost surely, 2^1966994891 is an apocalyptic number.

1966994891 is a deficient number, since it is larger than the sum of its proper divisors (86114869).

1966994891 is a wasteful number, since it uses less digits than its factorization.

1966994891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24745.

The product of its digits is 7558272, while the sum is 62.

The square root of 1966994891 is about 44350.8161255236. The cubic root of 1966994891 is about 1252.9519334635.

The spelling of 1966994891 in words is "one billion, nine hundred sixty-six million, nine hundred ninety-four thousand, eight hundred ninety-one".