21374280 has 112 divisors (see below), whose sum is σ = 72203580. Its totient is φ = 5692032.

The previous prime is 21374279. The next prime is 21374281. The reversal of 21374280 is 8247312.

It is an interprime number because it is at equal distance from previous prime (21374279) and next prime (21374281).

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 1285956 = 4482^2 + 1134^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21374281) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 28794 + ... + 29526.

Almost surely, 2^21374280 is an apocalyptic number.

21374280 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 21374280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36101790).

21374280 is an abundant number, since it is smaller than the sum of its proper divisors (50829300).

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

21374280 is an equidigital number, since it uses as much as digits as its factorization.

21374280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762 (or 743 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21374280 is about 4623.2326352889. The cubic root of 21374280 is about 277.5218390409.

The spelling of 21374280 in words is "twenty-one million, three hundred seventy-four thousand, two hundred eighty".