21494328 has 48 divisors (see below), whose sum is σ = 56206920. Its totient is φ = 6849216.

The previous prime is 21494311. The next prime is 21494329. The reversal of 21494328 is 82349412.

It is a super-2 number, since 2×21494328² = 924012272343168, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21494329) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11850 + ... + 13542.

Almost surely, 2^21494328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21494328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28103460).

21494328 is an abundant number, since it is smaller than the sum of its proper divisors (34712592).

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

21494328 is a wasteful number, since it uses less digits than its factorization.

21494328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748 (or 1721 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21494328 is about 4636.1975799140. The cubic root of 21494328 is about 278.0404337096.

The spelling of 21494328 in words is "twenty-one million, four hundred ninety-four thousand, three hundred twenty-eight".