20801040 has 160 divisors (see below), whose sum is σ = 71245440. Its totient is φ = 4988928.

The previous prime is 20801017. The next prime is 20801057. The reversal of 20801040 is 4010802.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 184024 + ... + 184136.

It is an arithmetic number, because the mean of its divisors is an integer number (445284).

Almost surely, 2^20801040 is an apocalyptic number.

20801040 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 20801040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35622720).

20801040 is an abundant number, since it is smaller than the sum of its proper divisors (50444400).

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

20801040 is a wasteful number, since it uses less digits than its factorization.

20801040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 20801040 is about 4560.8157165139. The cubic root of 20801040 is about 275.0183569013.

Adding to 20801040 its reverse (4010802), we get a palindrome (24811842).

The spelling of 20801040 in words is "twenty million, eight hundred one thousand, forty".