820156723 has 2 divisors, whose sum is σ = 820156724. Its totient is φ = 820156722.

The previous prime is 820156709. The next prime is 820156751. The reversal of 820156723 is 327651028.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 820156723 - 2¹³ = 820148531 is a prime.

It is not a weakly prime, because it can be changed into another prime (820156703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410078361 + 410078362.

It is an arithmetic number, because the mean of its divisors is an integer number (410078362).

Almost surely, 2^820156723 is an apocalyptic number.

820156723 is a deficient number, since it is larger than the sum of its proper divisors (1).

820156723 is an equidigital number, since it uses as much as digits as its factorization.

820156723 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 820156723 is about 28638.3784980924. The cubic root of 820156723 is about 936.0497890790.

The spelling of 820156723 in words is "eight hundred twenty million, one hundred fifty-six thousand, seven hundred twenty-three".