261065655213531 has 16 divisors (see below), whose sum is σ = 397814557440000. Its totient is φ = 149180289775488.

The previous prime is 261065655213527. The next prime is 261065655213541. The reversal of 261065655213531 is 135312556560162.

It is not a de Polignac number, because 261065655213531 - 2² = 261065655213527 is a prime.

It is a super-2 number, since 2×261065655213531² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261065655213541) 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, 71035635 + ... + 74620323.

It is an arithmetic number, because the mean of its divisors is an integer number (24863409840000).

Almost surely, 2^{261065655213531} is an apocalyptic number.

261065655213531 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

261065655213531 is a deficient number, since it is larger than the sum of its proper divisors (136748902226469).

261065655213531 is a wasteful number, since it uses less digits than its factorization.

261065655213531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7052698.

The product of its (nonzero) digits is 4860000, while the sum is 51.

The spelling of 261065655213531 in words is "two hundred sixty-one trillion, sixty-five billion, six hundred fifty-five million, two hundred thirteen thousand, five hundred thirty-one".