19871994 has 8 divisors (see below), whose sum is σ = 39744000. Its totient is φ = 6623996.

The previous prime is 19871953. The next prime is 19872001. The reversal of 19871994 is 49917891.

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

19871994 is an admirable number.

It is a super-2 number, since 2×19871994² = 789792291072072, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1655994 + ... + 1656005.

It is an arithmetic number, because the mean of its divisors is an integer number (4968000).

Almost surely, 2^19871994 is an apocalyptic number.

19871994 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

19871994 is a wasteful number, since it uses less digits than its factorization.

19871994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3312004.

The product of its digits is 163296, while the sum is 48.

The square root of 19871994 is about 4457.8014760642. The cubic root of 19871994 is about 270.8614188678.

The spelling of 19871994 in words is "nineteen million, eight hundred seventy-one thousand, nine hundred ninety-four".