72421506 has 64 divisors (see below), whose sum is σ = 168063360. Its totient is φ = 23094720.

The previous prime is 72421499. The next prime is 72421511. The reversal of 72421506 is 60512427.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 72421506.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133596 + ... + 134136.

It is an arithmetic number, because the mean of its divisors is an integer number (2625990).

Almost surely, 2^72421506 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72421506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84031680).

72421506 is an abundant number, since it is smaller than the sum of its proper divisors (95641854).

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

72421506 is a wasteful number, since it uses less digits than its factorization.

72421506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 650 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 72421506 is about 8510.0826082947. The cubic root of 72421506 is about 416.8270075878.

It can be divided in two parts, 72421 and 506, that added together give a palindrome (72927).

The spelling of 72421506 in words is "seventy-two million, four hundred twenty-one thousand, five hundred six".