261205455 has 16 divisors (see below), whose sum is σ = 477633024. Its totient is φ = 119408160.

The previous prime is 261205421. The next prime is 261205471. The reversal of 261205455 is 554502162.

It is not a de Polignac number, because 261205455 - 2¹⁶ = 261139919 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1243731 + ... + 1243940.

It is an arithmetic number, because the mean of its divisors is an integer number (29852064).

Almost surely, 2^261205455 is an apocalyptic number.

261205455 is a deficient number, since it is larger than the sum of its proper divisors (216427569).

261205455 is a wasteful number, since it uses less digits than its factorization.

261205455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2487686.

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 261205455 is about 16161.8518431521. The cubic root of 261205455 is about 639.2352967829.

The spelling of 261205455 in words is "two hundred sixty-one million, two hundred five thousand, four hundred fifty-five".