10640721 has 16 divisors (see below), whose sum is σ = 17462144. Its totient is φ = 5612544.

The previous prime is 10640701. The next prime is 10640723. The reversal of 10640721 is 12704601.

It is not a de Polignac number, because 10640721 - 2¹³ = 10632529 is a prime.

It is a super-2 number, since 2×10640721² = 226449886799682, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (10640723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19216 + ... + 19761.

It is an arithmetic number, because the mean of its divisors is an integer number (1091384).

Almost surely, 2^10640721 is an apocalyptic number.

It is an amenable number.

10640721 is a deficient number, since it is larger than the sum of its proper divisors (6821423).

10640721 is a wasteful number, since it uses less digits than its factorization.

10640721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39000.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 10640721 is about 3262.0118025538. The cubic root of 10640721 is about 219.9498577185.

The spelling of 10640721 in words is "ten million, six hundred forty thousand, seven hundred twenty-one".