261665454135 has 16 divisors (see below), whose sum is σ = 418701417696. Its totient is φ = 139542678528.

The previous prime is 261665454091. The next prime is 261665454179. The reversal of 261665454135 is 531454566162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261665454091) and next prime (261665454179).

It is not a de Polignac number, because 261665454135 - 2¹⁴ = 261665437751 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, 586194 + ... + 931103.

It is an arithmetic number, because the mean of its divisors is an integer number (26168838606).

Almost surely, 2^261665454135 is an apocalyptic number.

261665454135 is a deficient number, since it is larger than the sum of its proper divisors (157035963561).

261665454135 is a wasteful number, since it uses less digits than its factorization.

261665454135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528802.

The product of its digits is 2592000, while the sum is 48.

The spelling of 261665454135 in words is "two hundred sixty-one billion, six hundred sixty-five million, four hundred fifty-four thousand, one hundred thirty-five".