261564210617554 has 32 divisors (see below), whose sum is σ = 426305573809920. Its totient is φ = 119647082016000.

The previous prime is 261564210617513. The next prime is 261564210617617. The reversal of 261564210617554 is 455716012465162.

It is a junction number, because it is equal to n+sod(n) for n = 261564210617495 and 261564210617504.

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, 98434647 + ... + 101056954.

It is an arithmetic number, because the mean of its divisors is an integer number (13322049181560).

Almost surely, 2^{261564210617554} is an apocalyptic number.

261564210617554 is a deficient number, since it is larger than the sum of its proper divisors (164741363192366).

261564210617554 is a wasteful number, since it uses less digits than its factorization.

261564210617554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199492066.

The product of its (nonzero) digits is 12096000, while the sum is 55.

The spelling of 261564210617554 in words is "two hundred sixty-one trillion, five hundred sixty-four billion, two hundred ten million, six hundred seventeen thousand, five hundred fifty-four".