21986010 has 48 divisors (see below), whose sum is σ = 57507840. Its totient is φ = 5827680.

The previous prime is 21986009. The next prime is 21986017. The reversal of 21986010 is 1068912.

It is not an unprimeable number, because it can be changed into a prime (21986017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16551 + ... + 17829.

It is an arithmetic number, because the mean of its divisors is an integer number (1198080).

Almost surely, 2^21986010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21986010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28753920).

21986010 is an abundant number, since it is smaller than the sum of its proper divisors (35521830).

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

21986010 is a wasteful number, since it uses less digits than its factorization.

21986010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1483 (or 1480 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 21986010 is about 4688.9241836481. The cubic root of 21986010 is about 280.1445257284.

The spelling of 21986010 in words is "twenty-one million, nine hundred eighty-six thousand, ten".