72031161 has 4 divisors (see below), whose sum is σ = 96041552. Its totient is φ = 48020772.

The previous prime is 72031151. The next prime is 72031163. The reversal of 72031161 is 16113027.

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.

It is not a de Polignac number, because 72031161 - 2¹³ = 72022969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72031163) 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, 12005191 + ... + 12005196.

It is an arithmetic number, because the mean of its divisors is an integer number (24010388).

Almost surely, 2^72031161 is an apocalyptic number.

It is an amenable number.

72031161 is a deficient number, since it is larger than the sum of its proper divisors (24010391).

72031161 is a wasteful number, since it uses less digits than its factorization.

72031161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24010390.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 72031161 is about 8487.1173551448. The cubic root of 72031161 is about 416.0767721506.

Adding to 72031161 its reverse (16113027), we get a palindrome (88144188).

The spelling of 72031161 in words is "seventy-two million, thirty-one thousand, one hundred sixty-one".