72218029 has 4 divisors (see below), whose sum is σ = 77773276. Its totient is φ = 66662784.

The previous prime is 72218021. The next prime is 72218039. The reversal of 72218029 is 92081227.

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 10956100 + 61261929 = 3310^2 + 7827^2 .

It is a cyclic number.

It is not a de Polignac number, because 72218029 - 2³ = 72218021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72218021) 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, 2777604 + ... + 2777629.

It is an arithmetic number, because the mean of its divisors is an integer number (19443319).

Almost surely, 2^72218029 is an apocalyptic number.

It is an amenable number.

72218029 is a deficient number, since it is larger than the sum of its proper divisors (5555247).

72218029 is a wasteful number, since it uses less digits than its factorization.

72218029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5555246.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 72218029 is about 8498.1191448461. The cubic root of 72218029 is about 416.4362660786.

The spelling of 72218029 in words is "seventy-two million, two hundred eighteen thousand, twenty-nine".