10821681 has 40 divisors (see below), whose sum is σ = 17888640. Its totient is φ = 6477408.

The previous prime is 10821677. The next prime is 10821683. The reversal of 10821681 is 18612801.

It is not a de Polignac number, because 10821681 - 2² = 10821677 is a prime.

It is a super-2 number, since 2×10821681² = 234217559331522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (10821683) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 45160 + ... + 45398.

It is an arithmetic number, because the mean of its divisors is an integer number (447216).

Almost surely, 2^10821681 is an apocalyptic number.

It is an amenable number.

10821681 is a deficient number, since it is larger than the sum of its proper divisors (7066959).

10821681 is a wasteful number, since it uses less digits than its factorization.

10821681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 10821681 is about 3289.6323502787. The cubic root of 10821681 is about 221.1897049143.

The spelling of 10821681 in words is "ten million, eight hundred twenty-one thousand, six hundred eighty-one".