20597998 has 4 divisors (see below), whose sum is σ = 30897000. Its totient is φ = 10298998.

The previous prime is 20597971. The next prime is 20598001. The reversal of 20597998 is 89979502.

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

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5149498 + ... + 5149501.

It is an arithmetic number, because the mean of its divisors is an integer number (7724250).

Almost surely, 2^20597998 is an apocalyptic number.

20597998 is a deficient number, since it is larger than the sum of its proper divisors (10299002).

20597998 is a wasteful number, since it uses less digits than its factorization.

20597998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10299001.

The product of its (nonzero) digits is 408240, while the sum is 49.

The square root of 20597998 is about 4538.5017351545. The cubic root of 20597998 is about 274.1205979860.

The spelling of 20597998 in words is "twenty million, five hundred ninety-seven thousand, nine hundred ninety-eight".