72218406 has 32 divisors (see below), whose sum is σ = 160570368. Its totient is φ = 21503520.

The previous prime is 72218387. The next prime is 72218407. The reversal of 72218406 is 60481227.

It is a super-4 number, since 4×72218406⁴ (a number of 33 digits) contains 4444 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72218407) 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, 12516 + ... + 17351.

It is an arithmetic number, because the mean of its divisors is an integer number (5017824).

Almost surely, 2^72218406 is an apocalyptic number.

72218406 is an abundant number, since it is smaller than the sum of its proper divisors (88351962).

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

72218406 is a wasteful number, since it uses less digits than its factorization.

72218406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29916.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 72218406 is about 8498.1413261960. The cubic root of 72218406 is about 416.4369907185.

The spelling of 72218406 in words is "seventy-two million, two hundred eighteen thousand, four hundred six".