20045047 has 4 divisors (see below), whose sum is σ = 21867336. Its totient is φ = 18222760.

The previous prime is 20045017. The next prime is 20045063. The reversal of 20045047 is 74054002.

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 20045047 - 2⁷ = 20044919 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 (20045017) 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, 911128 + ... + 911149.

It is an arithmetic number, because the mean of its divisors is an integer number (5466834).

Almost surely, 2^20045047 is an apocalyptic number.

20045047 is a deficient number, since it is larger than the sum of its proper divisors (1822289).

20045047 is a wasteful number, since it uses less digits than its factorization.

20045047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1822288.

The product of its (nonzero) digits is 1120, while the sum is 22.

The square root of 20045047 is about 4477.1695299597. The cubic root of 20045047 is about 271.6454027962.

Adding to 20045047 its reverse (74054002), we get a palindrome (94099049).

The spelling of 20045047 in words is "twenty million, forty-five thousand, forty-seven".