261665054 has 16 divisors (see below), whose sum is σ = 474955488. Its totient is φ = 105545472.

The previous prime is 261665029. The next prime is 261665101. The reversal of 261665054 is 450566162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 549479 + ... + 549954.

It is an arithmetic number, because the mean of its divisors is an integer number (29684718).

Almost surely, 2^261665054 is an apocalyptic number.

261665054 is a deficient number, since it is larger than the sum of its proper divisors (213290434).

261665054 is a wasteful number, since it uses less digits than its factorization.

261665054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099459.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 261665054 is about 16176.0642308319. The cubic root of 261665054 is about 639.6099951335.

The spelling of 261665054 in words is "two hundred sixty-one million, six hundred sixty-five thousand, fifty-four".