72101857 has 2 divisors, whose sum is σ = 72101858. Its totient is φ = 72101856.

The previous prime is 72101839. The next prime is 72101951. The reversal of 72101857 is 75810127.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64256256 + 7845601 = 8016^2 + 2801^2 .

It is an emirp because it is prime and its reverse (75810127) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72101857 is a prime.

It is not a weakly prime, because it can be changed into another prime (72101357) 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, 36050928 + 36050929.

It is an arithmetic number, because the mean of its divisors is an integer number (36050929).

Almost surely, 2^72101857 is an apocalyptic number.

It is an amenable number.

72101857 is a deficient number, since it is larger than the sum of its proper divisors (1).

72101857 is an equidigital number, since it uses as much as digits as its factorization.

72101857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3920, while the sum is 31.

The square root of 72101857 is about 8491.2812343015. The cubic root of 72101857 is about 416.2128491163.

The spelling of 72101857 in words is "seventy-two million, one hundred one thousand, eight hundred fifty-seven".