1801172309 has 4 divisors (see below), whose sum is σ = 1801415616. Its totient is φ = 1800929004.

The previous prime is 1801172257. The next prime is 1801172311. The reversal of 1801172309 is 9032711081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1801172309 - 2¹⁶ = 1801106773 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 (1801172209) 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 in 3 ways as a sum of consecutive naturals, for example, 110189 + ... + 125474.

It is an arithmetic number, because the mean of its divisors is an integer number (450353904).

Almost surely, 2^1801172309 is an apocalyptic number.

It is an amenable number.

1801172309 is a deficient number, since it is larger than the sum of its proper divisors (243307).

1801172309 is an equidigital number, since it uses as much as digits as its factorization.

1801172309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243306.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 1801172309 is about 42440.2204164870. The cubic root of 1801172309 is about 1216.7044240321.

The spelling of 1801172309 in words is "one billion, eight hundred one million, one hundred seventy-two thousand, three hundred nine".