20198639 has 8 divisors (see below), whose sum is σ = 21087360. Its totient is φ = 19324800.

The previous prime is 20198627. The next prime is 20198657. The reversal of 20198639 is 93689102.

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

It is a cyclic number.

It is not a de Polignac number, because 20198639 - 2²⁴ = 3421423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20198039) 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, 902 + ... + 6419.

It is an arithmetic number, because the mean of its divisors is an integer number (2635920).

Almost surely, 2^20198639 is an apocalyptic number.

20198639 is a deficient number, since it is larger than the sum of its proper divisors (888721).

20198639 is an equidigital number, since it uses as much as digits as its factorization.

20198639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7441.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 20198639 is about 4494.2895990356. The cubic root of 20198639 is about 272.3374515245.

The spelling of 20198639 in words is "twenty million, one hundred ninety-eight thousand, six hundred thirty-nine".