72222145 has 4 divisors (see below), whose sum is σ = 86666580. Its totient is φ = 57777712.

The previous prime is 72222131. The next prime is 72222149. The reversal of 72222145 is 54122227.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43930384 + 28291761 = 6628^2 + 5319^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72222145 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72222149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7222210 + ... + 7222219.

It is an arithmetic number, because the mean of its divisors is an integer number (21666645).

Almost surely, 2^72222145 is an apocalyptic number.

It is an amenable number.

72222145 is a deficient number, since it is larger than the sum of its proper divisors (14444435).

72222145 is a wasteful number, since it uses less digits than its factorization.

72222145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14444434.

The product of its digits is 2240, while the sum is 25.

The square root of 72222145 is about 8498.3613126296. The cubic root of 72222145 is about 416.4441773954. Note that the first 3 decimals are identical.

The spelling of 72222145 in words is "seventy-two million, two hundred twenty-two thousand, one hundred forty-five".