20355140 has 48 divisors (see below), whose sum is σ = 46663680. Its totient is φ = 7413120.

The previous prime is 20355133. The next prime is 20355149. The reversal of 20355140 is 4155302.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (20355149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20045 + ... + 21035.

It is an arithmetic number, because the mean of its divisors is an integer number (972160).

Almost surely, 2^20355140 is an apocalyptic number.

20355140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20355140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23331840).

20355140 is an abundant number, since it is smaller than the sum of its proper divisors (26308540).

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

20355140 is a wasteful number, since it uses less digits than its factorization.

20355140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092 (or 1090 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20355140 is about 4511.6670976481. The cubic root of 20355140 is about 273.0390083221.

The spelling of 20355140 in words is "twenty million, three hundred fifty-five thousand, one hundred forty".