10721440 has 48 divisors (see below), whose sum is σ = 25596648. Its totient is φ = 4243456.

The previous prime is 10721419. The next prime is 10721461. The reversal of 10721440 is 4412701.

It is an interprime number because it is at equal distance from previous prime (10721419) and next prime (10721461).

It can be written as a sum of positive squares in 4 ways, for example, as 5934096 + 4787344 = 2436^2 + 2188^2 .

It is a super-2 number, since 2×10721440² = 229898551347200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17784 + ... + 18376.

Almost surely, 2^10721440 is an apocalyptic number.

10721440 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 10721440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12798324).

10721440 is an abundant number, since it is smaller than the sum of its proper divisors (14875208).

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

10721440 is a wasteful number, since it uses less digits than its factorization.

10721440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 10721440 is about 3274.3610063644. The cubic root of 10721440 is about 220.5046267474.

The spelling of 10721440 in words is "ten million, seven hundred twenty-one thousand, four hundred forty".