20908398 has 72 divisors (see below), whose sum is σ = 51599592. Its totient is φ = 5630688.

The previous prime is 20908397. The next prime is 20908399. The reversal of 20908398 is 89380902.

It is an interprime number because it is at equal distance from previous prime (20908397) and next prime (20908399).

It is a super-2 number, since 2×20908398² = 874322213852808, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20908397) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 106036 + ... + 106232.

It is an arithmetic number, because the mean of its divisors is an integer number (716661).

Almost surely, 2^20908398 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20908398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25799796).

20908398 is an abundant number, since it is smaller than the sum of its proper divisors (30691194).

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

20908398 is a wasteful number, since it uses less digits than its factorization.

20908398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 228 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 20908398 is about 4572.5701744205. The cubic root of 20908398 is about 275.4906853767.

The spelling of 20908398 in words is "twenty million, nine hundred eight thousand, three hundred ninety-eight".