261151439217 has 4 divisors (see below), whose sum is σ = 348201918960. Its totient is φ = 174100959476.

The previous prime is 261151439203. The next prime is 261151439221. The reversal of 261151439217 is 712934151162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261151439217 - 2¹⁹ = 261150914929 is a prime.

It is a super-2 number, since 2×261151439217² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261151439317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43525239867 + ... + 43525239872.

It is an arithmetic number, because the mean of its divisors is an integer number (87050479740).

Almost surely, 2^261151439217 is an apocalyptic number.

It is an amenable number.

261151439217 is a deficient number, since it is larger than the sum of its proper divisors (87050479743).

261151439217 is an equidigital number, since it uses as much as digits as its factorization.

261151439217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87050479742.

The product of its digits is 90720, while the sum is 42.

The spelling of 261151439217 in words is "two hundred sixty-one billion, one hundred fifty-one million, four hundred thirty-nine thousand, two hundred seventeen".