261758752642 has 4 divisors (see below), whose sum is σ = 392638128966. Its totient is φ = 130879376320.

The previous prime is 261758752637. The next prime is 261758752649. The reversal of 261758752642 is 246257857162.

It is a happy number.

261758752642 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 259691140801 + 2067611841 = 509599^2 + 45471^2 .

It is not an unprimeable number, because it can be changed into a prime (261758752649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65439688159 + ... + 65439688162.

Almost surely, 2^261758752642 is an apocalyptic number.

261758752642 is a deficient number, since it is larger than the sum of its proper divisors (130879376324).

261758752642 is a wasteful number, since it uses less digits than its factorization.

261758752642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130879376323.

The product of its digits is 11289600, while the sum is 55.

The spelling of 261758752642 in words is "two hundred sixty-one billion, seven hundred fifty-eight million, seven hundred fifty-two thousand, six hundred forty-two".