20699023 has 4 divisors (see below), whose sum is σ = 20814840. Its totient is φ = 20583208.

The previous prime is 20699009. The next prime is 20699033. The reversal of 20699023 is 32099602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32099602 = 2 ⋅16049801.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20699023 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20699033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57640 + ... + 57997.

It is an arithmetic number, because the mean of its divisors is an integer number (5203710).

Almost surely, 2^20699023 is an apocalyptic number.

20699023 is a deficient number, since it is larger than the sum of its proper divisors (115817).

20699023 is a wasteful number, since it uses less digits than its factorization.

20699023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115816.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 20699023 is about 4549.6178960436. The cubic root of 20699023 is about 274.5680181985.

The spelling of 20699023 in words is "twenty million, six hundred ninety-nine thousand, twenty-three".