20728398 has 16 divisors (see below), whose sum is σ = 42794496. Its totient is φ = 6686520.

The previous prime is 20728387. The next prime is 20728403. The reversal of 20728398 is 89382702.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55536 + ... + 55907.

It is an arithmetic number, because the mean of its divisors is an integer number (2674656).

Almost surely, 2^20728398 is an apocalyptic number.

20728398 is an abundant number, since it is smaller than the sum of its proper divisors (22066098).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20728398 is a wasteful number, since it uses less digits than its factorization.

20728398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111479.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 20728398 is about 4552.8450445848. The cubic root of 20728398 is about 274.6978411244.

The spelling of 20728398 in words is "twenty million, seven hundred twenty-eight thousand, three hundred ninety-eight".