157682821 has 2 divisors, whose sum is σ = 157682822. Its totient is φ = 157682820.

The previous prime is 157682783. The next prime is 157682887. The reversal of 157682821 is 128286751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114254721 + 43428100 = 10689^2 + 6590^2 .

It is an emirp because it is prime and its reverse (128286751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 157682821 - 2¹¹ = 157680773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157682891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78841410 + 78841411.

It is an arithmetic number, because the mean of its divisors is an integer number (78841411).

Almost surely, 2^157682821 is an apocalyptic number.

It is an amenable number.

157682821 is a deficient number, since it is larger than the sum of its proper divisors (1).

157682821 is an equidigital number, since it uses as much as digits as its factorization.

157682821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53760, while the sum is 40.

The square root of 157682821 is about 12557.1820485330. The cubic root of 157682821 is about 540.2500225379.

The spelling of 157682821 in words is "one hundred fifty-seven million, six hundred eighty-two thousand, eight hundred twenty-one".