72243131 has 2 divisors, whose sum is σ = 72243132. Its totient is φ = 72243130.

The previous prime is 72243109. The next prime is 72243137. The reversal of 72243131 is 13134227.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72243131 is a prime.

It is a super-2 number, since 2×72243131² = 10438139953366322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 72243097 and 72243106.

It is not a weakly prime, because it can be changed into another prime (72243137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36121565 + 36121566.

It is an arithmetic number, because the mean of its divisors is an integer number (36121566).

Almost surely, 2^72243131 is an apocalyptic number.

72243131 is a deficient number, since it is larger than the sum of its proper divisors (1).

72243131 is an equidigital number, since it uses as much as digits as its factorization.

72243131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 23.

The square root of 72243131 is about 8499.5959315723. The cubic root of 72243131 is about 416.4845096746.

Adding to 72243131 its reverse (13134227), we get a palindrome (85377358).

The spelling of 72243131 in words is "seventy-two million, two hundred forty-three thousand, one hundred thirty-one".