20967691 has 4 divisors (see below), whose sum is σ = 21004984. Its totient is φ = 20930400.

The previous prime is 20967689. The next prime is 20967707. The reversal of 20967691 is 19676902.

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 20967691 - 2¹ = 20967689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20967671) 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, 17790 + ... + 18931.

It is an arithmetic number, because the mean of its divisors is an integer number (5251246).

Almost surely, 2^20967691 is an apocalyptic number.

20967691 is a deficient number, since it is larger than the sum of its proper divisors (37293).

20967691 is an equidigital number, since it uses as much as digits as its factorization.

20967691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37292.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 20967691 is about 4579.0491371026. The cubic root of 20967691 is about 275.7508559968.

The spelling of 20967691 in words is "twenty million, nine hundred sixty-seven thousand, six hundred ninety-one".