20890440 has 192 divisors, whose sum is σ = 75254400. Its totient is φ = 5144832.

The previous prime is 20890409. The next prime is 20890447. The reversal of 20890440 is 4409802.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20890447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 720346 + ... + 720374.

It is an arithmetic number, because the mean of its divisors is an integer number (391950).

Almost surely, 2^20890440 is an apocalyptic number.

20890440 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 20890440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37627200).

20890440 is an abundant number, since it is smaller than the sum of its proper divisors (54363960).

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

20890440 is a wasteful number, since it uses less digits than its factorization.

20890440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20890440 is about 4570.6060867242. The cubic root of 20890440 is about 275.4117907815.

The spelling of 20890440 in words is "twenty million, eight hundred ninety thousand, four hundred forty".