72221424 has 80 divisors (see below), whose sum is σ = 208331904. Its totient is φ = 21369600.

The previous prime is 72221419. The next prime is 72221431. The reversal of 72221424 is 42412227.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 72221394 and 72221403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21114 + ... + 24294.

Almost surely, 2^72221424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72221424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104165952).

72221424 is an abundant number, since it is smaller than the sum of its proper divisors (136110480).

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

72221424 is a wasteful number, since it uses less digits than its factorization.

72221424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3246 (or 3240 counting only the distinct ones).

The product of its digits is 1792, while the sum is 24.

The square root of 72221424 is about 8498.3188925810. The cubic root of 72221424 is about 416.4427915912.

It can be divided in two parts, 7222 and 1424, that added together give a triangular number (8646 = T₁₃₁).

The spelling of 72221424 in words is "seventy-two million, two hundred twenty-one thousand, four hundred twenty-four".