72538856881 has 12 divisors (see below), whose sum is σ = 74298471156. Its totient is φ = 70795693280.

The previous prime is 72538856869. The next prime is 72538856891. The reversal of 72538856881 is 18865883527.

It can be written as a sum of positive squares in 2 ways, for example, as 44544213025 + 27994643856 = 211055^2 + 167316^2 .

It is not a de Polignac number, because 72538856881 - 2³¹ = 70391373233 is a prime.

It is a super-2 number, since 2×72538856881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72538856801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1914735 + ... + 1952251.

It is an arithmetic number, because the mean of its divisors is an integer number (6191539263).

Almost surely, 2^72538856881 is an apocalyptic number.

It is an amenable number.

72538856881 is a deficient number, since it is larger than the sum of its proper divisors (1759614275).

72538856881 is an equidigital number, since it uses as much as digits as its factorization.

72538856881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37952 (or 37761 counting only the distinct ones).

The product of its digits is 25804800, while the sum is 61.

The spelling of 72538856881 in words is "seventy-two billion, five hundred thirty-eight million, eight hundred fifty-six thousand, eight hundred eighty-one".