21867846 has 96 divisors (see below), whose sum is σ = 59345664. Its totient is φ = 5227200.

The previous prime is 21867823. The next prime is 21867869. The reversal of 21867846 is 64876812.

It is an interprime number because it is at equal distance from previous prime (21867823) and next prime (21867869).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21867798 and 21867807.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 65901 + ... + 66231.

It is an arithmetic number, because the mean of its divisors is an integer number (618184).

Almost surely, 2^21867846 is an apocalyptic number.

21867846 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21867846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29672832).

21867846 is an abundant number, since it is smaller than the sum of its proper divisors (37477818).

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

21867846 is a wasteful number, since it uses less digits than its factorization.

21867846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 367 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 21867846 is about 4676.3068761577. The cubic root of 21867846 is about 279.6417441935.

The spelling of 21867846 in words is "twenty-one million, eight hundred sixty-seven thousand, eight hundred forty-six".