8021691 has 12 divisors (see below), whose sum is σ = 11870040. Its totient is φ = 5217120.

The previous prime is 8021681. The next prime is 8021729. The reversal of 8021691 is 1961208.

It is not a de Polignac number, because 8021691 - 2⁶ = 8021627 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8021681) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10501 + ... + 11238.

It is an arithmetic number, because the mean of its divisors is an integer number (989170).

Almost surely, 2^8021691 is an apocalyptic number.

8021691 is a deficient number, since it is larger than the sum of its proper divisors (3848349).

8021691 is a wasteful number, since it uses less digits than its factorization.

8021691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21786 (or 21783 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 8021691 is about 2832.2589923946. The cubic root of 8021691 is about 200.1805952111.

Adding to 8021691 its reverse (1961208), we get a palindrome (9982899).

The spelling of 8021691 in words is "eight million, twenty-one thousand, six hundred ninety-one".