20791619 has 4 divisors (see below), whose sum is σ = 20802744. Its totient is φ = 20780496.

The previous prime is 20791613. The next prime is 20791621. The reversal of 20791619 is 91619702.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 91619702 = 2 ⋅45809851.

It is a cyclic number.

It is not a de Polignac number, because 20791619 - 2⁸ = 20791363 is a prime.

It is a super-2 number, since 2×20791619² = 864582841282322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20791613) 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 3 ways as a sum of consecutive naturals, for example, 1997 + ... + 6750.

It is an arithmetic number, because the mean of its divisors is an integer number (5200686).

Almost surely, 2^20791619 is an apocalyptic number.

20791619 is a deficient number, since it is larger than the sum of its proper divisors (11125).

20791619 is an equidigital number, since it uses as much as digits as its factorization.

20791619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11124.

The product of its (nonzero) digits is 6804, while the sum is 35.

The square root of 20791619 is about 4559.7827799140. The cubic root of 20791619 is about 274.9768311059.

The spelling of 20791619 in words is "twenty million, seven hundred ninety-one thousand, six hundred nineteen".