72106551 has 32 divisors (see below), whose sum is σ = 117676800. Its totient is φ = 43273440.

The previous prime is 72106549. The next prime is 72106579. The reversal of 72106551 is 15560127.

72106551 is a `hidden beast` number, since 7 + 2 + 1 + 0 + 655 + 1 = 666.

It is not a de Polignac number, because 72106551 - 2¹ = 72106549 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72106591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30645 + ... + 32913.

It is an arithmetic number, because the mean of its divisors is an integer number (3677400).

Almost surely, 2^72106551 is an apocalyptic number.

72106551 is a deficient number, since it is larger than the sum of its proper divisors (45570249).

72106551 is a wasteful number, since it uses less digits than its factorization.

72106551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2396 (or 2390 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 72106551 is about 8491.5576309650. The cubic root of 72106551 is about 416.2218810646.

Adding to 72106551 its reverse (15560127), we get a palindrome (87666678).

The spelling of 72106551 in words is "seventy-two million, one hundred six thousand, five hundred fifty-one".