20805379 has 4 divisors (see below), whose sum is σ = 23777584. Its totient is φ = 17833176.

The previous prime is 20805377. The next prime is 20805397. The reversal of 20805379 is 97350802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97350802 = 2 ⋅48675401.

It is a cyclic number.

It is not a de Polignac number, because 20805379 - 2¹ = 20805377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20805373) 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, 1486092 + ... + 1486105.

It is an arithmetic number, because the mean of its divisors is an integer number (5944396).

Almost surely, 2^20805379 is an apocalyptic number.

20805379 is a deficient number, since it is larger than the sum of its proper divisors (2972205).

20805379 is an equidigital number, since it uses as much as digits as its factorization.

20805379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2972204.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20805379 is about 4561.2913741615. The cubic root of 20805379 is about 275.0374780877.

The spelling of 20805379 in words is "twenty million, eight hundred five thousand, three hundred seventy-nine".