156406561 has 2 divisors, whose sum is σ = 156406562. Its totient is φ = 156406560.

The previous prime is 156406531. The next prime is 156406597. The reversal of 156406561 is 165604651.

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., 128686336 + 27720225 = 11344^2 + 5265^2 .

It is a cyclic number.

It is not a de Polignac number, because 156406561 - 2⁵ = 156406529 is a prime.

It is not a weakly prime, because it can be changed into another prime (156406531) 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, 78203280 + 78203281.

It is an arithmetic number, because the mean of its divisors is an integer number (78203281).

Almost surely, 2^156406561 is an apocalyptic number.

It is an amenable number.

156406561 is a deficient number, since it is larger than the sum of its proper divisors (1).

156406561 is an equidigital number, since it uses as much as digits as its factorization.

156406561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 156406561 is about 12506.2608720592. The cubic root of 156406561 is about 538.7885060306.

It can be divided in two parts, 15640 and 6561, that added together give a square (22201 = 149²).

The spelling of 156406561 in words is "one hundred fifty-six million, four hundred six thousand, five hundred sixty-one".