161217755 has 16 divisors (see below), whose sum is σ = 207982080. Its totient is φ = 119583072.

The previous prime is 161217751. The next prime is 161217761. The reversal of 161217755 is 557712161.

It is a cyclic number.

It is not a de Polignac number, because 161217755 - 2² = 161217751 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161217751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13589 + ... + 22518.

It is an arithmetic number, because the mean of its divisors is an integer number (12998880).

Almost surely, 2^161217755 is an apocalyptic number.

161217755 is a deficient number, since it is larger than the sum of its proper divisors (46764325).

161217755 is a wasteful number, since it uses less digits than its factorization.

161217755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36178.

The product of its digits is 14700, while the sum is 35.

The square root of 161217755 is about 12697.1553900864. The cubic root of 161217755 is about 544.2573336925.

The spelling of 161217755 in words is "one hundred sixty-one million, two hundred seventeen thousand, seven hundred fifty-five".