72221646 has 32 divisors (see below), whose sum is σ = 165496320. Its totient is φ = 20582496.

The previous prime is 72221561. The next prime is 72221647. The reversal of 72221646 is 64612227.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72221647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16480 + ... + 20396.

It is an arithmetic number, because the mean of its divisors is an integer number (5171760).

Almost surely, 2^72221646 is an apocalyptic number.

72221646 is an abundant number, since it is smaller than the sum of its proper divisors (93274674).

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

72221646 is a wasteful number, since it uses less digits than its factorization.

72221646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4368.

The product of its digits is 8064, while the sum is 30.

The square root of 72221646 is about 8498.3319539778. The cubic root of 72221646 is about 416.4432182892.

The spelling of 72221646 in words is "seventy-two million, two hundred twenty-one thousand, six hundred forty-six".