20427791 has 4 divisors (see below), whose sum is σ = 21086784. Its totient is φ = 19768800.

The previous prime is 20427787. The next prime is 20427817. The reversal of 20427791 is 19772402.

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 20427791 - 2² = 20427787 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 (20457791) 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, 329450 + ... + 329511.

It is an arithmetic number, because the mean of its divisors is an integer number (5271696).

Almost surely, 2^20427791 is an apocalyptic number.

20427791 is a deficient number, since it is larger than the sum of its proper divisors (658993).

20427791 is an equidigital number, since it uses as much as digits as its factorization.

20427791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658992.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 20427791 is about 4519.7113845908. The cubic root of 20427791 is about 273.3634636955.

The spelling of 20427791 in words is "twenty million, four hundred twenty-seven thousand, seven hundred ninety-one".