19901994 has 16 divisors (see below), whose sum is σ = 45490368. Its totient is φ = 5686272.

The previous prime is 19901963. The next prime is 19902011. The reversal of 19901994 is 49910991.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 473857 = 19901994 / (1 + 9 + 9 + 0 + 1 + 9 + 9 + 4).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236887 + ... + 236970.

It is an arithmetic number, because the mean of its divisors is an integer number (2843148).

Almost surely, 2^19901994 is an apocalyptic number.

19901994 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

19901994 is an abundant number, since it is smaller than the sum of its proper divisors (25588374).

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

19901994 is a wasteful number, since it uses less digits than its factorization.

19901994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473869.

The product of its (nonzero) digits is 26244, while the sum is 42.

The square root of 19901994 is about 4461.1650944568. The cubic root of 19901994 is about 270.9976534249.

The spelling of 19901994 in words is "nineteen million, nine hundred one thousand, nine hundred ninety-four".