72543547 has 4 divisors (see below), whose sum is σ = 72564840. Its totient is φ = 72522256.

The previous prime is 72543511. The next prime is 72543563. The reversal of 72543547 is 74534527.

It is a happy number.

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

It is a 4-Lehmer number, since φ(72543547) divides (72543547-1)⁴.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72543547 is a prime.

It is a super-2 number, since 2×72543547² = 10525132422682418, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72543047) 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, 4258 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (18141210).

It is a Poulet number, since it divides 2^72543546-1.

Almost surely, 2^72543547 is an apocalyptic number.

72543547 is the 4259-th decagonal number.

72543547 is a deficient number, since it is larger than the sum of its proper divisors (21293).

72543547 is a wasteful number, since it uses less digits than its factorization.

72543547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21292.

The product of its digits is 117600, while the sum is 37.

The square root of 72543547 is about 8517.2499669788. The cubic root of 72543547 is about 417.0610146752.

It can be divided in two parts, 7254 and 3547, that added together give a palindrome (10801).

The spelling of 72543547 in words is "seventy-two million, five hundred forty-three thousand, five hundred forty-seven".