261534542877 has 48 divisors (see below), whose sum is σ = 405463443840. Its totient is φ = 168264879552.

The previous prime is 261534542873. The next prime is 261534542891. The reversal of 261534542877 is 778245435162.

261534542877 is a `hidden beast` number, since 2 + 6 + 15 + 3 + 4 + 542 + 87 + 7 = 666.

It is not a de Polignac number, because 261534542877 - 2² = 261534542873 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261534542873) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17447928 + ... + 17462910.

It is an arithmetic number, because the mean of its divisors is an integer number (8447155080).

Almost surely, 2^261534542877 is an apocalyptic number.

261534542877 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

261534542877 is a deficient number, since it is larger than the sum of its proper divisors (143928900963).

261534542877 is a wasteful number, since it uses less digits than its factorization.

261534542877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17504 (or 17492 counting only the distinct ones).

The product of its digits is 11289600, while the sum is 54.

The spelling of 261534542877 in words is "two hundred sixty-one billion, five hundred thirty-four million, five hundred forty-two thousand, eight hundred seventy-seven".