261989144619 has 4 divisors (see below), whose sum is σ = 349318859496. Its totient is φ = 174659429744.

The previous prime is 261989144597. The next prime is 261989144741. The reversal of 261989144619 is 916441989162.

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

It is a cyclic number.

It is not a de Polignac number, because 261989144619 - 2⁹ = 261989144107 is a prime.

It is a super-2 number, since 2×261989144619² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261989144519) 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, 43664857434 + ... + 43664857439.

It is an arithmetic number, because the mean of its divisors is an integer number (87329714874).

Almost surely, 2^261989144619 is an apocalyptic number.

261989144619 is a deficient number, since it is larger than the sum of its proper divisors (87329714877).

261989144619 is an equidigital number, since it uses as much as digits as its factorization.

261989144619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87329714876.

The product of its digits is 6718464, while the sum is 60.

The spelling of 261989144619 in words is "two hundred sixty-one billion, nine hundred eighty-nine million, one hundred forty-four thousand, six hundred nineteen".