21798546 has 64 divisors (see below), whose sum is σ = 56263680. Its totient is φ = 5463360.

The previous prime is 21798541. The next prime is 21798547. The reversal of 21798546 is 64589712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21798498 and 21798507.

It is not an unprimeable number, because it can be changed into a prime (21798541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12585 + ... + 14211.

It is an arithmetic number, because the mean of its divisors is an integer number (879120).

Almost surely, 2^21798546 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21798546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28131840).

21798546 is an abundant number, since it is smaller than the sum of its proper divisors (34465134).

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

21798546 is a wasteful number, since it uses less digits than its factorization.

21798546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1679.

The product of its digits is 120960, while the sum is 42.

The square root of 21798546 is about 4668.8913030826. The cubic root of 21798546 is about 279.3460333114.

The spelling of 21798546 in words is "twenty-one million, seven hundred ninety-eight thousand, five hundred forty-six".