20801580 has 96 divisors (see below), whose sum is σ = 62415360. Its totient is φ = 5160960.

The previous prime is 20801579. The next prime is 20801593. The reversal of 20801580 is 8510802.

It is a self number, because there is not a number n which added to its sum of digits gives 20801580.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80812 + ... + 81068.

It is an arithmetic number, because the mean of its divisors is an integer number (650160).

Almost surely, 2^20801580 is an apocalyptic number.

20801580 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 20801580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31207680).

20801580 is an abundant number, since it is smaller than the sum of its proper divisors (41613780).

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

20801580 is a wasteful number, since it uses less digits than its factorization.

20801580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 20801580 is about 4560.8749160660. The cubic root of 20801580 is about 275.0207367283.

The spelling of 20801580 in words is "twenty million, eight hundred one thousand, five hundred eighty".