72144551 has 4 divisors (see below), whose sum is σ = 73367400. Its totient is φ = 70921704.

The previous prime is 72144529. The next prime is 72144563. The reversal of 72144551 is 15544127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15544127 = 149 ⋅104323.

It is a cyclic number.

It is not a de Polignac number, because 72144551 - 2¹⁰ = 72143527 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 (72144521) 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, 611336 + ... + 611453.

It is an arithmetic number, because the mean of its divisors is an integer number (18341850).

Almost surely, 2^72144551 is an apocalyptic number.

72144551 is a deficient number, since it is larger than the sum of its proper divisors (1222849).

72144551 is a wasteful number, since it uses less digits than its factorization.

72144551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1222848.

The product of its digits is 5600, while the sum is 29.

The square root of 72144551 is about 8493.7948527145. The cubic root of 72144551 is about 416.2949842416.

Adding to 72144551 its reverse (15544127), we get a palindrome (87688678).

The spelling of 72144551 in words is "seventy-two million, one hundred forty-four thousand, five hundred fifty-one".