72175861 has 2 divisors, whose sum is σ = 72175862. Its totient is φ = 72175860.

The previous prime is 72175853. The next prime is 72175919. The reversal of 72175861 is 16857127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68989636 + 3186225 = 8306^2 + 1785^2 .

It is a cyclic number.

It is not a de Polignac number, because 72175861 - 2³ = 72175853 is a prime.

It is a super-2 number, since 2×72175861² = 10418709822182642, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 72175861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72175361) 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, 36087930 + 36087931.

It is an arithmetic number, because the mean of its divisors is an integer number (36087931).

Almost surely, 2^72175861 is an apocalyptic number.

It is an amenable number.

72175861 is a deficient number, since it is larger than the sum of its proper divisors (1).

72175861 is an equidigital number, since it uses as much as digits as its factorization.

72175861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23520, while the sum is 37.

The square root of 72175861 is about 8495.6377629934. The cubic root of 72175861 is about 416.3551981254.

The spelling of 72175861 in words is "seventy-two million, one hundred seventy-five thousand, eight hundred sixty-one".