10921681 has 4 divisors (see below), whose sum is σ = 10937200. Its totient is φ = 10906164.

The previous prime is 10921649. The next prime is 10921693. The reversal of 10921681 is 18612901.

It is a happy number.

10921681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18612901 = 1559 ⋅11939.

It is a cyclic number.

It is not a de Polignac number, because 10921681 - 2⁵ = 10921649 is a prime.

It is a super-2 number, since 2×10921681² = 238566231731522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (10924681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6651 + ... + 8128.

It is an arithmetic number, because the mean of its divisors is an integer number (2734300).

Almost surely, 2^10921681 is an apocalyptic number.

It is an amenable number.

10921681 is a deficient number, since it is larger than the sum of its proper divisors (15519).

10921681 is an equidigital number, since it uses as much as digits as its factorization.

10921681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15518.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 10921681 is about 3304.7966654546. The cubic root of 10921681 is about 221.8689335378.

The spelling of 10921681 in words is "ten million, nine hundred twenty-one thousand, six hundred eighty-one".