20365691 has 2 divisors, whose sum is σ = 20365692. Its totient is φ = 20365690.

The previous prime is 20365637. The next prime is 20365693. The reversal of 20365691 is 19656302.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20365691 - 2¹⁸ = 20103547 is a prime.

It is a super-2 number, since 2×20365691² = 829522739814962, which contains 22 as substring.

Together with 20365693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20365693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10182845 + 10182846.

It is an arithmetic number, because the mean of its divisors is an integer number (10182846).

Almost surely, 2^20365691 is an apocalyptic number.

20365691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20365691 is an equidigital number, since it uses as much as digits as its factorization.

20365691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20365691 is about 4512.8362478601. The cubic root of 20365691 is about 273.0861763750.

The spelling of 20365691 in words is "twenty million, three hundred sixty-five thousand, six hundred ninety-one".