161020261 has 16 divisors (see below), whose sum is σ = 169302528. Its totient is φ = 153014400.

The previous prime is 161020259. The next prime is 161020273. The reversal of 161020261 is 162020161.

It is a cyclic number.

It is not a de Polignac number, because 161020261 - 2¹ = 161020259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161020061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 243271 + ... + 243931.

It is an arithmetic number, because the mean of its divisors is an integer number (10581408).

Almost surely, 2^161020261 is an apocalyptic number.

It is an amenable number.

161020261 is a deficient number, since it is larger than the sum of its proper divisors (8282267).

161020261 is an equidigital number, since it uses as much as digits as its factorization.

161020261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 161020261 is about 12689.3759105797. The cubic root of 161020261 is about 544.0350019380.

The spelling of 161020261 in words is "one hundred sixty-one million, twenty thousand, two hundred sixty-one".