72218020 has 24 divisors (see below), whose sum is σ = 173323584. Its totient is φ = 24760416.

The previous prime is 72218017. The next prime is 72218021. The reversal of 72218020 is 2081227.

It is a junction number, because it is equal to n+sod(n) for n = 72217982 and 72218000.

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 7 ways as a sum of consecutive naturals, for example, 257782 + ... + 258061.

It is an arithmetic number, because the mean of its divisors is an integer number (7221816).

Almost surely, 2^72218020 is an apocalyptic number.

72218020 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

72218020 is an abundant number, since it is smaller than the sum of its proper divisors (101105564).

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

72218020 is a wasteful number, since it uses less digits than its factorization.

72218020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515859 (or 515857 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 72218020 is about 8498.1186153172. The cubic root of 72218020 is about 416.4362487795.

Adding to 72218020 its reverse (2081227), we get a palindrome (74299247).

The spelling of 72218020 in words is "seventy-two million, two hundred eighteen thousand, twenty".