21682458 has 64 divisors (see below), whose sum is σ = 57984000. Its totient is φ = 5866992.

The previous prime is 21682433. The next prime is 21682487. The reversal of 21682458 is 85428612.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5673 + ... + 8691.

It is an arithmetic number, because the mean of its divisors is an integer number (906000).

Almost surely, 2^21682458 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21682458, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28992000).

21682458 is an abundant number, since it is smaller than the sum of its proper divisors (36301542).

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

21682458 is a wasteful number, since it uses less digits than its factorization.

21682458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3056 (or 3050 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 21682458 is about 4656.4426335992. The cubic root of 21682458 is about 278.8492653229.

The spelling of 21682458 in words is "twenty-one million, six hundred eighty-two thousand, four hundred fifty-eight".