72217451 has 4 divisors (see below), whose sum is σ = 74169312. Its totient is φ = 70265592.

The previous prime is 72217421. The next prime is 72217463. The reversal of 72217451 is 15471227.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15471227 = 41 ⋅377347.

It is a cyclic number.

It is not a de Polignac number, because 72217451 - 2¹⁴ = 72201067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72217421) 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, 975875 + ... + 975948.

It is an arithmetic number, because the mean of its divisors is an integer number (18542328).

Almost surely, 2^72217451 is an apocalyptic number.

72217451 is a deficient number, since it is larger than the sum of its proper divisors (1951861).

72217451 is a wasteful number, since it uses less digits than its factorization.

72217451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1951860.

The product of its digits is 3920, while the sum is 29.

The square root of 72217451 is about 8498.0851372530. The cubic root of 72217451 is about 416.4351550873.

Adding to 72217451 its reverse (15471227), we get a palindrome (87688678).

The spelling of 72217451 in words is "seventy-two million, two hundred seventeen thousand, four hundred fifty-one".