20397798 has 16 divisors (see below), whose sum is σ = 45328560. Its totient is φ = 6799248.

The previous prime is 20397763. The next prime is 20397809. The reversal of 20397798 is 89779302.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

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, 188815 + ... + 188922.

It is an arithmetic number, because the mean of its divisors is an integer number (2833035).

Almost surely, 2^20397798 is an apocalyptic number.

20397798 is an abundant number, since it is smaller than the sum of its proper divisors (24930762).

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

20397798 is a wasteful number, since it uses less digits than its factorization.

20397798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377748 (or 377742 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 20397798 is about 4516.3921441788. The cubic root of 20397798 is about 273.2296099934.

The spelling of 20397798 in words is "twenty million, three hundred ninety-seven thousand, seven hundred ninety-eight".