1801724436 has 18 divisors (see below), whose sum is σ = 4554359082. Its totient is φ = 600574800.

The previous prime is 1801724399. The next prime is 1801724437. The reversal of 1801724436 is 6344271081.

It can be written as a sum of positive squares in only one way, i.e., 1799456400 + 2268036 = 42420^2 + 1506^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 50047901 = 1801724436 / (1 + 8 + 0 + 1 + 7 + 2 + 4 + 4 + 3 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 1801724436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801724437) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25023915 + ... + 25023986.

It is an arithmetic number, because the mean of its divisors is an integer number (253019949).

Almost surely, 2^1801724436 is an apocalyptic number.

It is an amenable number.

1801724436 is an abundant number, since it is smaller than the sum of its proper divisors (2752634646).

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

1801724436 is a wasteful number, since it uses less digits than its factorization.

1801724436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50047911 (or 50047906 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 1801724436 is about 42446.7246792965. The cubic root of 1801724436 is about 1216.8287332075.

The spelling of 1801724436 in words is "one billion, eight hundred one million, seven hundred twenty-four thousand, four hundred thirty-six".