72100031 has 2 divisors, whose sum is σ = 72100032. Its totient is φ = 72100030.

The previous prime is 72100027. The next prime is 72100037. The reversal of 72100031 is 13000127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 72100031 - 2² = 72100027 is a prime.

It is a super-3 number, since 3×72100031³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 72099979 and 72100015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72100037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36050015 + 36050016.

It is an arithmetic number, because the mean of its divisors is an integer number (36050016).

Almost surely, 2^72100031 is an apocalyptic number.

72100031 is a deficient number, since it is larger than the sum of its proper divisors (1).

72100031 is an equidigital number, since it uses as much as digits as its factorization.

72100031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 72100031 is about 8491.1737115666. The cubic root of 72100031 is about 416.2093355172.

Adding to 72100031 its reverse (13000127), we get a palindrome (85100158).

The spelling of 72100031 in words is "seventy-two million, one hundred thousand, thirty-one".