72535681 has 4 divisors (see below), whose sum is σ = 72879664. Its totient is φ = 72191700.

The previous prime is 72535679. The next prime is 72535703. The reversal of 72535681 is 18653527.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18653527 = 569 ⋅32783.

It is a cyclic number.

It is not a de Polignac number, because 72535681 - 2¹ = 72535679 is a prime.

It is a super-2 number, since 2×72535681² = 10522850036267522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72535681.

It is not an unprimeable number, because it can be changed into a prime (72535081) 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 3 ways as a sum of consecutive naturals, for example, 171675 + ... + 172096.

It is an arithmetic number, because the mean of its divisors is an integer number (18219916).

Almost surely, 2^72535681 is an apocalyptic number.

It is an amenable number.

72535681 is a deficient number, since it is larger than the sum of its proper divisors (343983).

72535681 is a wasteful number, since it uses less digits than its factorization.

72535681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343982.

The product of its digits is 50400, while the sum is 37.

The square root of 72535681 is about 8516.7881856954. The cubic root of 72535681 is about 417.0459399573.

The spelling of 72535681 in words is "seventy-two million, five hundred thirty-five thousand, six hundred eighty-one".