20007691 has 8 divisors (see below), whose sum is σ = 23110704. Its totient is φ = 17118720.

The previous prime is 20007683. The next prime is 20007719. The reversal of 20007691 is 19670002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20007691 - 2³ = 20007683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20007601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53310 + ... + 53683.

It is an arithmetic number, because the mean of its divisors is an integer number (2888838).

Almost surely, 2^20007691 is an apocalyptic number.

20007691 is a deficient number, since it is larger than the sum of its proper divisors (3103013).

20007691 is a wasteful number, since it uses less digits than its factorization.

20007691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107021.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 20007691 is about 4472.9957522895. The cubic root of 20007691 is about 271.4765515102.

Adding to 20007691 its reverse (19670002), we get a palindrome (39677693).

The spelling of 20007691 in words is "twenty million, seven thousand, six hundred ninety-one".