72143861 has 2 divisors, whose sum is σ = 72143862. Its totient is φ = 72143860.

The previous prime is 72143837. The next prime is 72143867. The reversal of 72143861 is 16834127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53567761 + 18576100 = 7319^2 + 4310^2 .

It is an emirp because it is prime and its reverse (16834127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72143861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72143867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36071930 + 36071931.

It is an arithmetic number, because the mean of its divisors is an integer number (36071931).

Almost surely, 2^72143861 is an apocalyptic number.

It is an amenable number.

72143861 is a deficient number, since it is larger than the sum of its proper divisors (1).

72143861 is an equidigital number, since it uses as much as digits as its factorization.

72143861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 32.

The square root of 72143861 is about 8493.7542347304. The cubic root of 72143861 is about 416.2936570706.

Adding to 72143861 its reverse (16834127), we get a palindrome (88977988).

The spelling of 72143861 in words is "seventy-two million, one hundred forty-three thousand, eight hundred sixty-one".