20445779 has 4 divisors (see below), whose sum is σ = 20492376. Its totient is φ = 20399184.

The previous prime is 20445773. The next prime is 20445791. The reversal of 20445779 is 97754402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97754402 = 2 ⋅48877201.

It is a cyclic number.

It is not a de Polignac number, because 20445779 - 2²⁴ = 3668563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20445773) 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, 22634 + ... + 23519.

It is an arithmetic number, because the mean of its divisors is an integer number (5123094).

Almost surely, 2^20445779 is an apocalyptic number.

20445779 is a deficient number, since it is larger than the sum of its proper divisors (46597).

20445779 is an equidigital number, since it uses as much as digits as its factorization.

20445779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46596.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 20445779 is about 4521.7008967865. The cubic root of 20445779 is about 273.4436782648.

The spelling of 20445779 in words is "twenty million, four hundred forty-five thousand, seven hundred seventy-nine".