72417551 has 4 divisors (see below), whose sum is σ = 72435504. Its totient is φ = 72399600.

The previous prime is 72417523. The next prime is 72417571. The reversal of 72417551 is 15571427.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72417551 - 2⁶ = 72417487 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 (72417571) 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, 206 + ... + 12036.

It is an arithmetic number, because the mean of its divisors is an integer number (18108876).

Almost surely, 2^72417551 is an apocalyptic number.

72417551 is a deficient number, since it is larger than the sum of its proper divisors (17953).

72417551 is a wasteful number, since it uses less digits than its factorization.

72417551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17952.

The product of its digits is 9800, while the sum is 32.

The square root of 72417551 is about 8509.8502336998. The cubic root of 72417551 is about 416.8194196906.

Adding to 72417551 its reverse (15571427), we get a palindrome (87988978).

The spelling of 72417551 in words is "seventy-two million, four hundred seventeen thousand, five hundred fifty-one".