19955881 has 8 divisors (see below), whose sum is σ = 22716864. Its totient is φ = 17352720.

The previous prime is 19955861. The next prime is 19955893. The reversal of 19955881 is 18855991.

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

It is not a de Polignac number, because 19955881 - 2⁷ = 19955753 is a prime.

It is a super-2 number, since 2×19955881² = 796474372972322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19955801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39186 + ... + 39691.

It is an arithmetic number, because the mean of its divisors is an integer number (2839608).

Almost surely, 2^19955881 is an apocalyptic number.

19955881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19955881 is a deficient number, since it is larger than the sum of its proper divisors (2760983).

19955881 is a wasteful number, since it uses less digits than its factorization.

19955881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78911.

The product of its digits is 129600, while the sum is 46.

The square root of 19955881 is about 4467.2005775429. The cubic root of 19955881 is about 271.2420190620.

The spelling of 19955881 in words is "nineteen million, nine hundred fifty-five thousand, eight hundred eighty-one".