72191808 has 168 divisors, whose sum is σ = 230770176. Its totient is φ = 21427200.

The previous prime is 72191789. The next prime is 72191813. The reversal of 72191808 is 80819127.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 231973 + ... + 232283.

It is an arithmetic number, because the mean of its divisors is an integer number (1373632).

Almost surely, 2^72191808 is an apocalyptic number.

72191808 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72191808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115385088).

72191808 is an abundant number, since it is smaller than the sum of its proper divisors (158578368).

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

72191808 is a wasteful number, since it uses less digits than its factorization.

72191808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 72191808 is about 8496.5762516440. The cubic root of 72191808 is about 416.3858599345.

It can be divided in two parts, 721 and 91808, that added together give a palindrome (92529).

The spelling of 72191808 in words is "seventy-two million, one hundred ninety-one thousand, eight hundred eight".