21861846 has 16 divisors (see below), whose sum is σ = 48582000. Its totient is φ = 7287264.

The previous prime is 21861839. The next prime is 21861859. The reversal of 21861846 is 64816812.

It is a self number, because there is not a number n which added to its sum of digits gives 21861846.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202371 + ... + 202478.

It is an arithmetic number, because the mean of its divisors is an integer number (3036375).

Almost surely, 2^21861846 is an apocalyptic number.

21861846 is an abundant number, since it is smaller than the sum of its proper divisors (26720154).

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

21861846 is a wasteful number, since it uses less digits than its factorization.

21861846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404860 (or 404854 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 21861846 is about 4675.6653002541. The cubic root of 21861846 is about 279.6161662446.

The spelling of 21861846 in words is "twenty-one million, eight hundred sixty-one thousand, eight hundred forty-six".