261216355 has 16 divisors (see below), whose sum is σ = 318931200. Its totient is φ = 205352928.

The previous prime is 261216353. The next prime is 261216409. The reversal of 261216355 is 553612162.

It is a cyclic number.

It is not a de Polignac number, because 261216355 - 2¹ = 261216353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261216353) 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, 81004 + ... + 84166.

It is an arithmetic number, because the mean of its divisors is an integer number (19933200).

Almost surely, 2^261216355 is an apocalyptic number.

261216355 is a deficient number, since it is larger than the sum of its proper divisors (57714845).

261216355 is a wasteful number, since it uses less digits than its factorization.

261216355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3450.

The product of its digits is 10800, while the sum is 31.

The square root of 261216355 is about 16162.1890534667. The cubic root of 261216355 is about 639.2441883377.

The spelling of 261216355 in words is "two hundred sixty-one million, two hundred sixteen thousand, three hundred fifty-five".