18941639 has 4 divisors (see below), whose sum is σ = 18970056. Its totient is φ = 18913224.

The previous prime is 18941633. The next prime is 18941707. The reversal of 18941639 is 93614981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18941639 - 2⁴ = 18941623 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18941596 and 18941605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18941633) 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, 13184 + ... + 14549.

It is an arithmetic number, because the mean of its divisors is an integer number (4742514).

Almost surely, 2^18941639 is an apocalyptic number.

18941639 is a deficient number, since it is larger than the sum of its proper divisors (28417).

18941639 is an equidigital number, since it uses as much as digits as its factorization.

18941639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28416.

The product of its digits is 46656, while the sum is 41.

The square root of 18941639 is about 4352.1993290749. The cubic root of 18941639 is about 266.5666730998.

The spelling of 18941639 in words is "eighteen million, nine hundred forty-one thousand, six hundred thirty-nine".