156840391 has 2 divisors, whose sum is σ = 156840392. Its totient is φ = 156840390.

The previous prime is 156840379. The next prime is 156840403. The reversal of 156840391 is 193048651.

156840391 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (156840379) and next prime (156840403).

It is a cyclic number.

It is not a de Polignac number, because 156840391 - 2¹³ = 156832199 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 156840391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156840311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78420195 + 78420196.

It is an arithmetic number, because the mean of its divisors is an integer number (78420196).

Almost surely, 2^156840391 is an apocalyptic number.

156840391 is the 7231-st hex number.

156840391 is a deficient number, since it is larger than the sum of its proper divisors (1).

156840391 is an equidigital number, since it uses as much as digits as its factorization.

156840391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 156840391 is about 12523.5933741079. The cubic root of 156840391 is about 539.2861979332.

The spelling of 156840391 in words is "one hundred fifty-six million, eight hundred forty thousand, three hundred ninety-one".