261564252540667 has 8 divisors (see below), whose sum is σ = 272697088215024. Its totient is φ = 250660959870048.

The previous prime is 261564252540659. The next prime is 261564252540683. The reversal of 261564252540667 is 766045252465162.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261564252540667 - 2³ = 261564252540659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261564252540167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57385748608 + ... + 57385753165.

It is an arithmetic number, because the mean of its divisors is an integer number (34087136026878).

Almost surely, 2^{261564252540667} is an apocalyptic number.

261564252540667 is a deficient number, since it is larger than the sum of its proper divisors (11132835674357).

261564252540667 is a wasteful number, since it uses less digits than its factorization.

261564252540667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114771501869.

The product of its (nonzero) digits is 145152000, while the sum is 61.

The spelling of 261564252540667 in words is "two hundred sixty-one trillion, five hundred sixty-four billion, two hundred fifty-two million, five hundred forty thousand, six hundred sixty-seven".