21048720 has 320 divisors, whose sum is σ = 87422976. Its totient is φ = 4055040.

The previous prime is 21048707. The next prime is 21048757. The reversal of 21048720 is 2784012.

It is a super-2 number, since 2×21048720² = 886097227276800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 314127 + ... + 314193.

Almost surely, 2^21048720 is an apocalyptic number.

21048720 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 21048720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43711488).

21048720 is an abundant number, since it is smaller than the sum of its proper divisors (66374256).

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

21048720 is a wasteful number, since it uses less digits than its factorization.

21048720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 21048720 is about 4587.8884031763. Note that the first 3 decimals coincide. The cubic root of 21048720 is about 276.1056096575.

The spelling of 21048720 in words is "twenty-one million, forty-eight thousand, seven hundred twenty".