261516435811 has 8 divisors (see below), whose sum is σ = 267605333424. Its totient is φ = 255427861920.

The previous prime is 261516435787. The next prime is 261516435821. The reversal of 261516435811 is 118534615162.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261516435811 - 2¹⁷ = 261516304739 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261516435821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2501121 + ... + 2603581.

It is an arithmetic number, because the mean of its divisors is an integer number (33450666678).

Almost surely, 2^261516435811 is an apocalyptic number.

261516435811 is a deficient number, since it is larger than the sum of its proper divisors (6088897613).

261516435811 is a wasteful number, since it uses less digits than its factorization.

261516435811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161861.

The product of its digits is 172800, while the sum is 43.

The spelling of 261516435811 in words is "two hundred sixty-one billion, five hundred sixteen million, four hundred thirty-five thousand, eight hundred eleven".