261664776015533 has 16 divisors (see below), whose sum is σ = 304279795276800. Its totient is φ = 222504600268080.

The previous prime is 261664776015499. The next prime is 261664776015583. The reversal of 261664776015533 is 335510677466162.

It is a cyclic number.

It is not a de Polignac number, because 261664776015533 - 2¹² = 261664776011437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261664776015583) 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, 7923936491 + ... + 7923969512.

It is an arithmetic number, because the mean of its divisors is an integer number (19017487204800).

Almost surely, 2^{261664776015533} is an apocalyptic number.

It is an amenable number.

261664776015533 is a deficient number, since it is larger than the sum of its proper divisors (42615019261267).

261664776015533 is a wasteful number, since it uses less digits than its factorization.

261664776015533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15847906112.

The product of its (nonzero) digits is 114307200, while the sum is 62.

The spelling of 261664776015533 in words is "two hundred sixty-one trillion, six hundred sixty-four billion, seven hundred seventy-six million, fifteen thousand, five hundred thirty-three".