20398040 has 32 divisors (see below), whose sum is σ = 49427280. Its totient is φ = 7531392.

The previous prime is 20398013. The next prime is 20398043. The reversal of 20398040 is 4089302.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20398043) 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, 19094 + ... + 20133.

Almost surely, 2^20398040 is an apocalyptic number.

20398040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20398040 is an abundant number, since it is smaller than the sum of its proper divisors (29029240).

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

20398040 is a wasteful number, since it uses less digits than its factorization.

20398040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39251 (or 39247 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20398040 is about 4516.4189353956. The cubic root of 20398040 is about 273.2306905235.

The spelling of 20398040 in words is "twenty million, three hundred ninety-eight thousand, forty".