261063057006864 has 720 divisors, whose sum is σ = 872810570536320. Its totient is φ = 72611591270400.

The previous prime is 261063057006803. The next prime is 261063057006877. The reversal of 261063057006864 is 468600750360162.

261063057006864 is a `hidden beast` number, since 2 + 6 + 1 + 0 + 6 + 3 + 0 + 570 + 0 + 6 + 8 + 64 = 666.

It is a super-2 number, since 2×261063057006864² (a number of 30 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261063057006864.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 12211180527 + ... + 12211201905.

Almost surely, 2^{261063057006864} is an apocalyptic number.

261063057006864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261063057006864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (436405285268160).

261063057006864 is an abundant number, since it is smaller than the sum of its proper divisors (611747513529456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261063057006864 is a wasteful number, since it uses less digits than its factorization.

261063057006864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21788 (or 21772 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 54.

The spelling of 261063057006864 in words is "two hundred sixty-one trillion, sixty-three billion, fifty-seven million, six thousand, eight hundred sixty-four".