161556725266 has 16 divisors (see below), whose sum is σ = 246467093400. Its totient is φ = 79402740480.

The previous prime is 161556725263. The next prime is 161556725303. The reversal of 161556725266 is 662527655161.

It can be written as a sum of positive squares in 4 ways, for example, as 97393302241 + 64163423025 = 312079^2 + 253305^2 .

It is a super-2 number, since 2×161556725266² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161556725263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238471 + ... + 616426.

Almost surely, 2^161556725266 is an apocalyptic number.

161556725266 is a deficient number, since it is larger than the sum of its proper divisors (84910368134).

161556725266 is a wasteful number, since it uses less digits than its factorization.

161556725266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 856509.

The product of its digits is 4536000, while the sum is 52.

The spelling of 161556725266 in words is "one hundred sixty-one billion, five hundred fifty-six million, seven hundred twenty-five thousand, two hundred sixty-six".