19955988 has 36 divisors (see below), whose sum is σ = 54325908. Its totient is φ = 6140160.

The previous prime is 19955963. The next prime is 19955989. The reversal of 19955988 is 88955991.

19955988 is a `hidden beast` number, since 1 + 9 + 9 + 559 + 88 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7551504 + 12404484 = 2748^2 + 3522^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×19955988² = 796482914112288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19955989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20853 + ... + 21788.

It is an arithmetic number, because the mean of its divisors is an integer number (1509053).

Almost surely, 2^19955988 is an apocalyptic number.

19955988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

19955988 is an abundant number, since it is smaller than the sum of its proper divisors (34369920).

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

19955988 is a wasteful number, since it uses less digits than its factorization.

19955988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42664 (or 42659 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 54.

The square root of 19955988 is about 4467.2125537073. The cubic root of 19955988 is about 271.2425038455.

The spelling of 19955988 in words is "nineteen million, nine hundred fifty-five thousand, nine hundred eighty-eight".