20438173191 has 16 divisors (see below), whose sum is σ = 27466905600. Its totient is φ = 13517870688.

The previous prime is 20438173181. The next prime is 20438173193. The reversal of 20438173191 is 19137183402.

It is not a de Polignac number, because 20438173191 - 2⁹ = 20438172679 is a prime.

It is a super-2 number, since 2×20438173191² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20438173193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 139890 + ... + 245856.

It is an arithmetic number, because the mean of its divisors is an integer number (1716681600).

Almost surely, 2^20438173191 is an apocalyptic number.

20438173191 is a deficient number, since it is larger than the sum of its proper divisors (7028732409).

20438173191 is a wasteful number, since it uses less digits than its factorization.

20438173191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106478.

The product of its (nonzero) digits is 36288, while the sum is 39.

The spelling of 20438173191 in words is "twenty billion, four hundred thirty-eight million, one hundred seventy-three thousand, one hundred ninety-one".