72217556 has 12 divisors (see below), whose sum is σ = 133032480. Its totient is φ = 34208280.

The previous prime is 72217531. The next prime is 72217571. The reversal of 72217556 is 65571227.

It is a happy number.

It is a super-2 number, since 2×72217556² = 10430750789226272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 475040 + ... + 475191.

It is an arithmetic number, because the mean of its divisors is an integer number (11086040).

Almost surely, 2^72217556 is an apocalyptic number.

72217556 is a gapful number since it is divisible by the number (76) formed by its first and last digit.

It is an amenable number.

72217556 is a deficient number, since it is larger than the sum of its proper divisors (60814924).

72217556 is a wasteful number, since it uses less digits than its factorization.

72217556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950254 (or 950252 counting only the distinct ones).

The product of its digits is 29400, while the sum is 35.

The square root of 72217556 is about 8498.0913151131. The cubic root of 72217556 is about 416.4353569115.

The spelling of 72217556 in words is "seventy-two million, two hundred seventeen thousand, five hundred fifty-six".