20030172091 has 2 divisors, whose sum is σ = 20030172092. Its totient is φ = 20030172090.

The previous prime is 20030172079. The next prime is 20030172161. The reversal of 20030172091 is 19027103002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20030172091 - 2⁵ = 20030172059 is a prime.

It is not a weakly prime, because it can be changed into another prime (20030170091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10015086045 + 10015086046.

It is an arithmetic number, because the mean of its divisors is an integer number (10015086046).

Almost surely, 2^20030172091 is an apocalyptic number.

20030172091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20030172091 is an equidigital number, since it uses as much as digits as its factorization.

20030172091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

Adding to 20030172091 its reverse (19027103002), we get a palindrome (39057275093).

The spelling of 20030172091 in words is "twenty billion, thirty million, one hundred seventy-two thousand, ninety-one".