156865993 has 2 divisors, whose sum is σ = 156865994. Its totient is φ = 156865992.

The previous prime is 156865991. The next prime is 156865999. The reversal of 156865993 is 399568651.

156865993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155950144 + 915849 = 12488^2 + 957^2 .

It is a cyclic number.

It is not a de Polignac number, because 156865993 - 2¹ = 156865991 is a prime.

Together with 156865991, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 156865993.

It is not a weakly prime, because it can be changed into another prime (156865991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78432996 + 78432997.

It is an arithmetic number, because the mean of its divisors is an integer number (78432997).

Almost surely, 2^156865993 is an apocalyptic number.

It is an amenable number.

156865993 is a deficient number, since it is larger than the sum of its proper divisors (1).

156865993 is an equidigital number, since it uses as much as digits as its factorization.

156865993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1749600, while the sum is 52.

The square root of 156865993 is about 12524.6154831196. The cubic root of 156865993 is about 539.3155399796.

The spelling of 156865993 in words is "one hundred fifty-six million, eight hundred sixty-five thousand, nine hundred ninety-three".