261166455 has 48 divisors (see below), whose sum is σ = 497296800. Its totient is φ = 125740800.

The previous prime is 261166441. The next prime is 261166459. The reversal of 261166455 is 554661162.

261166455 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 6 + 645 + 5 = 666.

It is not a de Polignac number, because 261166455 - 2⁴ = 261166439 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261166459) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 71985 + ... + 75525.

It is an arithmetic number, because the mean of its divisors is an integer number (10360350).

Almost surely, 2^261166455 is an apocalyptic number.

261166455 is a deficient number, since it is larger than the sum of its proper divisors (236130345).

261166455 is a wasteful number, since it uses less digits than its factorization.

261166455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3712 (or 3709 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 261166455 is about 16160.6452532069. The cubic root of 261166455 is about 639.2034809371.

The spelling of 261166455 in words is "two hundred sixty-one million, one hundred sixty-six thousand, four hundred fifty-five".