20841849405 has 24 divisors (see below), whose sum is σ = 38904786648. Its totient is φ = 10260602496.

The previous prime is 20841849323. The next prime is 20841849407. The reversal of 20841849405 is 50494814802.

It can be written as a sum of positive squares in 4 ways, for example, as 224910009 + 20616939396 = 14997^2 + 143586^2 .

It is not a de Polignac number, because 20841849405 - 2²⁵ = 20808294973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20841849407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17812962 + ... + 17814131.

It is an arithmetic number, because the mean of its divisors is an integer number (1621032777).

Almost surely, 2^20841849405 is an apocalyptic number.

It is an amenable number.

20841849405 is a deficient number, since it is larger than the sum of its proper divisors (18062937243).

20841849405 is a wasteful number, since it uses less digits than its factorization.

20841849405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35627117 (or 35627114 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 20841849405 in words is "twenty billion, eight hundred forty-one million, eight hundred forty-nine thousand, four hundred five".