20021998 has 8 divisors (see below), whose sum is σ = 30095640. Its totient is φ = 9990120.

The previous prime is 20021951. The next prime is 20021999. The reversal of 20021998 is 89912002.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021999) 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, 9213 + ... + 11176.

It is an arithmetic number, because the mean of its divisors is an integer number (3761955).

Almost surely, 2^20021998 is an apocalyptic number.

20021998 is a deficient number, since it is larger than the sum of its proper divisors (10073642).

20021998 is a wasteful number, since it uses less digits than its factorization.

20021998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20882.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20021998 is about 4474.5947302521. The cubic root of 20021998 is about 271.5412447925.

The spelling of 20021998 in words is "twenty million, twenty-one thousand, nine hundred ninety-eight".