1809329172 has 48 divisors (see below), whose sum is σ = 4831572480. Its totient is φ = 516233952.

The previous prime is 1809329143. The next prime is 1809329173. The reversal of 1809329172 is 2719239081.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809329173) 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, 47503 + ... + 76649.

It is an arithmetic number, because the mean of its divisors is an integer number (100657760).

Almost surely, 2^1809329172 is an apocalyptic number.

1809329172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1809329172 is an abundant number, since it is smaller than the sum of its proper divisors (3022243308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1809329172 is a wasteful number, since it uses less digits than its factorization.

1809329172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29900 (or 29898 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 1809329172 is about 42536.2101273727. The cubic root of 1809329172 is about 1218.5383310086.

Subtracting 1809329172 from its reverse (2719239081), we obtain a palindrome (909909909).

The spelling of 1809329172 in words is "one billion, eight hundred nine million, three hundred twenty-nine thousand, one hundred seventy-two".