19951988 has 12 divisors (see below), whose sum is σ = 39904032. Its totient is φ = 8550840.

The previous prime is 19951961. The next prime is 19952011. The reversal of 19951988 is 88915991.

19951988 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356258 + ... + 356313.

It is an arithmetic number, because the mean of its divisors is an integer number (3325336).

Almost surely, 2^19951988 is an apocalyptic number.

It is an amenable number.

19951988 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.

19951988 is a wasteful number, since it uses less digits than its factorization.

19951988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 712582 (or 712580 counting only the distinct ones).

The product of its digits is 233280, while the sum is 50.

The square root of 19951988 is about 4466.7648247921. The cubic root of 19951988 is about 271.2243799200.

The spelling of 19951988 in words is "nineteen million, nine hundred fifty-one thousand, nine hundred eighty-eight".