10655721 has 6 divisors (see below), whose sum is σ = 15391610. Its totient is φ = 7103808.

The previous prime is 10655707. The next prime is 10655767. The reversal of 10655721 is 12755601.

10655721 is a `hidden beast` number, since 1 + 0 + 655 + 7 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10653696 + 2025 = 3264^2 + 45^2 .

It is not a de Polignac number, because 10655721 - 2¹¹ = 10653673 is a prime.

It is a super-2 number, since 2×10655721² = 227088780059682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10655791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 591976 + ... + 591993.

Almost surely, 2^10655721 is an apocalyptic number.

It is an amenable number.

10655721 is a deficient number, since it is larger than the sum of its proper divisors (4735889).

10655721 is a wasteful number, since it uses less digits than its factorization.

10655721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1183975 (or 1183972 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 10655721 is about 3264.3101874669. The cubic root of 10655721 is about 220.0531620837.

It can be divided in two parts, 1065 and 5721, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 10655721 in words is "ten million, six hundred fifty-five thousand, seven hundred twenty-one".