10821720 has 128 divisors (see below), whose sum is σ = 39997440. Its totient is φ = 2280960.

The previous prime is 10821719. The next prime is 10821757. The reversal of 10821720 is 2712801.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10425 + ... + 11415.

It is an arithmetic number, because the mean of its divisors is an integer number (312480).

Almost surely, 2^10821720 is an apocalyptic number.

10821720 is a gapful number since it is divisible by the number (10) 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 10821720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19998720).

10821720 is an abundant number, since it is smaller than the sum of its proper divisors (29175720).

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

10821720 is a wasteful number, since it uses less digits than its factorization.

10821720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025 (or 1021 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 10821720 is about 3289.6382779874. The cubic root of 10821720 is about 221.1899706274.

The spelling of 10821720 in words is "ten million, eight hundred twenty-one thousand, seven hundred twenty".