20860840 has 128 divisors (see below), whose sum is σ = 63141120. Its totient is φ = 5990400.

The previous prime is 20860823. The next prime is 20860871. The reversal of 20860840 is 4806802.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 20860799 and 20860808.

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, 39780 + ... + 40300.

It is an arithmetic number, because the mean of its divisors is an integer number (493290).

Almost surely, 2^20860840 is an apocalyptic number.

20860840 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 20860840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31570560).

20860840 is an abundant number, since it is smaller than the sum of its proper divisors (42280280).

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

20860840 is a wasteful number, since it uses less digits than its factorization.

20860840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563 (or 559 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 20860840 is about 4567.3668562970. The cubic root of 20860840 is about 275.2816508329.

The spelling of 20860840 in words is "twenty million, eight hundred sixty thousand, eight hundred forty".