161256745 has 8 divisors (see below), whose sum is σ = 208393416. Its totient is φ = 119081856.

The previous prime is 161256727. The next prime is 161256757. The reversal of 161256745 is 547652161.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2421136 + 158835609 = 1556^2 + 12603^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161256745 - 2²³ = 152868137 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1240372 + ... + 1240501.

It is an arithmetic number, because the mean of its divisors is an integer number (26049177).

Almost surely, 2^161256745 is an apocalyptic number.

It is an amenable number.

161256745 is a deficient number, since it is larger than the sum of its proper divisors (47136671).

161256745 is a wasteful number, since it uses less digits than its factorization.

161256745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2480891.

The product of its digits is 50400, while the sum is 37.

The square root of 161256745 is about 12698.6906805387. The cubic root of 161256745 is about 544.3012057895.

The spelling of 161256745 in words is "one hundred sixty-one million, two hundred fifty-six thousand, seven hundred forty-five".