21474320 has 80 divisors (see below), whose sum is σ = 58948608. Its totient is φ = 7119360.

The previous prime is 21474293. The next prime is 21474353. The reversal of 21474320 is 2347412.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×21474320² = 922292838924800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16742 + ... + 17978.

Almost surely, 2^21474320 is an apocalyptic number.

21474320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21474320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29474304).

21474320 is an abundant number, since it is smaller than the sum of its proper divisors (37474288).

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

21474320 is a wasteful number, since it uses less digits than its factorization.

21474320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1288 (or 1282 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21474320 is about 4634.0392747580. The cubic root of 21474320 is about 277.9541355940.

The spelling of 21474320 in words is "twenty-one million, four hundred seventy-four thousand, three hundred twenty".