72181404 has 18 divisors (see below), whose sum is σ = 182458640. Its totient is φ = 24060456.

The previous prime is 72181397. The next prime is 72181409. The reversal of 72181404 is 40418127.

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

It is a super-2 number, since 2×72181404² = 10420310166822432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72181409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1002484 + ... + 1002555.

Almost surely, 2^72181404 is an apocalyptic number.

It is an amenable number.

72181404 is an abundant number, since it is smaller than the sum of its proper divisors (110277236).

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

72181404 is a wasteful number, since it uses less digits than its factorization.

72181404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2005049 (or 2005044 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 72181404 is about 8495.9639829745. The cubic root of 72181404 is about 416.3658563416.

It can be divided in two parts, 72 and 181404, that added together give a square (181476 = 426²).

The spelling of 72181404 in words is "seventy-two million, one hundred eighty-one thousand, four hundred four".