261620163 has 30 divisors (see below), whose sum is σ = 440888604. Its totient is φ = 149484888.

The previous prime is 261620159. The next prime is 261620167. The reversal of 261620163 is 361026162.

261620163 is a `hidden beast` number, since 26 + 1 + 620 + 16 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (261620159) and next prime (261620167).

It is not a de Polignac number, because 261620163 - 2² = 261620159 is a prime.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (261620167) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 15556 + ... + 27662.

Almost surely, 2^261620163 is an apocalyptic number.

261620163 is a deficient number, since it is larger than the sum of its proper divisors (179268441).

261620163 is an equidigital number, since it uses as much as digits as its factorization.

261620163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12141 (or 12117 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 261620163 is about 16174.6765964578. The cubic root of 261620163 is about 639.5734160871.

The spelling of 261620163 in words is "two hundred sixty-one million, six hundred twenty thousand, one hundred sixty-three".