72013778181 has 6 divisors (see below), whose sum is σ = 104019901830. Its totient is φ = 48009185448.

The previous prime is 72013778167. The next prime is 72013778191. The reversal of 72013778181 is 18187731027.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 40397382081 + 31616396100 = 200991^2 + 177810^2 .

It is not a de Polignac number, because 72013778181 - 2⁹ = 72013777669 is a prime.

It is a super-2 number, since 2×72013778181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72013778191) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4000765446 + ... + 4000765463.

It is an arithmetic number, because the mean of its divisors is an integer number (17336650305).

Almost surely, 2^72013778181 is an apocalyptic number.

It is an amenable number.

72013778181 is a deficient number, since it is larger than the sum of its proper divisors (32006123649).

72013778181 is a wasteful number, since it uses less digits than its factorization.

72013778181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8001530915 (or 8001530912 counting only the distinct ones).

The product of its (nonzero) digits is 131712, while the sum is 45.

The spelling of 72013778181 in words is "seventy-two billion, thirteen million, seven hundred seventy-eight thousand, one hundred eighty-one".