1994368643 has 4 divisors (see below), whose sum is σ = 1996834680. Its totient is φ = 1991902608.

The previous prime is 1994368631. The next prime is 1994368661. The reversal of 1994368643 is 3468634991.

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

It is a cyclic number.

It is not a de Polignac number, because 1994368643 - 2²⁶ = 1927259779 is a prime.

It is a super-2 number, since 2×1994368643² = 7955012568363322898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1994368603) 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 3 ways as a sum of consecutive naturals, for example, 1231805 + ... + 1233422.

It is an arithmetic number, because the mean of its divisors is an integer number (499208670).

Almost surely, 2^1994368643 is an apocalyptic number.

1994368643 is a deficient number, since it is larger than the sum of its proper divisors (2466037).

1994368643 is an equidigital number, since it uses as much as digits as its factorization.

1994368643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2466036.

The product of its digits is 3359232, while the sum is 53.

The square root of 1994368643 is about 44658.3546830825. The cubic root of 1994368643 is about 1258.7374274281.

The spelling of 1994368643 in words is "one billion, nine hundred ninety-four million, three hundred sixty-eight thousand, six hundred forty-three".