19885381 has 4 divisors (see below), whose sum is σ = 20932000. Its totient is φ = 18838764.

The previous prime is 19885379. The next prime is 19885423. The reversal of 19885381 is 18358891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19885381 - 2¹ = 19885379 is a prime.

It is a super-2 number, since 2×19885381² = 790856755030322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19885331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 523281 + ... + 523318.

It is an arithmetic number, because the mean of its divisors is an integer number (5233000).

Almost surely, 2^19885381 is an apocalyptic number.

It is an amenable number.

19885381 is a deficient number, since it is larger than the sum of its proper divisors (1046619).

19885381 is a wasteful number, since it uses less digits than its factorization.

19885381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046618.

The product of its digits is 69120, while the sum is 43.

The square root of 19885381 is about 4459.3027481883. The cubic root of 19885381 is about 270.9222281971.

The spelling of 19885381 in words is "nineteen million, eight hundred eighty-five thousand, three hundred eighty-one".