20138798 has 4 divisors (see below), whose sum is σ = 30208200. Its totient is φ = 10069398.

The previous prime is 20138743. The next prime is 20138801. The reversal of 20138798 is 89783102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89783102 = 2 ⋅44891551.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5034698 + ... + 5034701.

It is an arithmetic number, because the mean of its divisors is an integer number (7552050).

Almost surely, 2^20138798 is an apocalyptic number.

20138798 is a deficient number, since it is larger than the sum of its proper divisors (10069402).

20138798 is a wasteful number, since it uses less digits than its factorization.

20138798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10069401.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 20138798 is about 4487.6272126816. The cubic root of 20138798 is about 272.0682408796.

The spelling of 20138798 in words is "twenty million, one hundred thirty-eight thousand, seven hundred ninety-eight".