20168819 has 4 divisors (see below), whose sum is σ = 22002360. Its totient is φ = 18335280.

The previous prime is 20168803. The next prime is 20168821. The reversal of 20168819 is 91886102.

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 20168819 - 2⁴ = 20168803 is a prime.

It is a super-2 number, since 2×20168819² = 813562519709522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20168839) 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, 916754 + ... + 916775.

It is an arithmetic number, because the mean of its divisors is an integer number (5500590).

Almost surely, 2^20168819 is an apocalyptic number.

20168819 is a deficient number, since it is larger than the sum of its proper divisors (1833541).

20168819 is a wasteful number, since it uses less digits than its factorization.

20168819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1833540.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 20168819 is about 4490.9708304553. The cubic root of 20168819 is about 272.2033648899.

The spelling of 20168819 in words is "twenty million, one hundred sixty-eight thousand, eight hundred nineteen".