10821691 has 4 divisors (see below), whose sum is σ = 10842984. Its totient is φ = 10800400.

The previous prime is 10821689. The next prime is 10821709. The reversal of 10821691 is 19612801.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 10821691 - 2¹ = 10821689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10821631) 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, 9865 + ... + 10906.

It is an arithmetic number, because the mean of its divisors is an integer number (2710746).

Almost surely, 2^10821691 is an apocalyptic number.

10821691 is a deficient number, since it is larger than the sum of its proper divisors (21293).

10821691 is an equidigital number, since it uses as much as digits as its factorization.

10821691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21292.

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

The square root of 10821691 is about 3289.6338702050. The cubic root of 10821691 is about 221.1897730459.

The spelling of 10821691 in words is "ten million, eight hundred twenty-one thousand, six hundred ninety-one".