21485320 has 16 divisors (see below), whose sum is σ = 48342060. Its totient is φ = 8594112.

The previous prime is 21485291. The next prime is 21485327. The reversal of 21485320 is 2358412.

It can be written as a sum of positive squares in 2 ways, for example, as 21178404 + 306916 = 4602^2 + 554^2 .

It is not an unprimeable number, because it can be changed into a prime (21485327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268527 + ... + 268606.

Almost surely, 2^21485320 is an apocalyptic number.

21485320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21485320 is an abundant number, since it is smaller than the sum of its proper divisors (26856740).

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

21485320 is a wasteful number, since it uses less digits than its factorization.

21485320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537144 (or 537140 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 21485320 is about 4635.2259923331. The cubic root of 21485320 is about 278.0015872104.

The spelling of 21485320 in words is "twenty-one million, four hundred eighty-five thousand, three hundred twenty".