20998398 has 16 divisors (see below), whose sum is σ = 42045696. Its totient is φ = 6991320.

The previous prime is 20998387. The next prime is 20998399. The reversal of 20998398 is 89389902.

20998398 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20998399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5965 + ... + 8807.

It is an arithmetic number, because the mean of its divisors is an integer number (2627856).

Almost surely, 2^20998398 is an apocalyptic number.

20998398 is an abundant number, since it is smaller than the sum of its proper divisors (21047298).

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

20998398 is a wasteful number, since it uses less digits than its factorization.

20998398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4079.

The product of its (nonzero) digits is 279936, while the sum is 48.

The square root of 20998398 is about 4582.4008990921. The cubic root of 20998398 is about 275.8854019097.

The spelling of 20998398 in words is "twenty million, nine hundred ninety-eight thousand, three hundred ninety-eight".