21860900 has 36 divisors (see below), whose sum is σ = 48121920. Its totient is φ = 8618400.

The previous prime is 21860897. The next prime is 21860933. The reversal of 21860900 is 906812.

It is a self number, because there is not a number n which added to its sum of digits gives 21860900.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5561 + ... + 8639.

It is an arithmetic number, because the mean of its divisors is an integer number (1336720).

Almost surely, 2^21860900 is an apocalyptic number.

21860900 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 21860900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24060960).

21860900 is an abundant number, since it is smaller than the sum of its proper divisors (26261020).

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

21860900 is a wasteful number, since it uses less digits than its factorization.

21860900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3164 (or 3157 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21860900 is about 4675.5641370855. The cubic root of 21860900 is about 279.6121330276.

The spelling of 21860900 in words is "twenty-one million, eight hundred sixty thousand, nine hundred".