261506520167 has 4 divisors (see below), whose sum is σ = 264095693736. Its totient is φ = 258917346600.

The previous prime is 261506520161. The next prime is 261506520173. The reversal of 261506520167 is 761025605162.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (261506520161) and next prime (261506520173).

It is a cyclic number.

It is not a de Polignac number, because 261506520167 - 2⁶ = 261506520103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261506520161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1294586633 + ... + 1294586834.

It is an arithmetic number, because the mean of its divisors is an integer number (66023923434).

Almost surely, 2^261506520167 is an apocalyptic number.

261506520167 is a deficient number, since it is larger than the sum of its proper divisors (2589173569).

261506520167 is a wasteful number, since it uses less digits than its factorization.

261506520167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2589173568.

The product of its (nonzero) digits is 151200, while the sum is 41.

The spelling of 261506520167 in words is "two hundred sixty-one billion, five hundred six million, five hundred twenty thousand, one hundred sixty-seven".