261251061982 has 4 divisors (see below), whose sum is σ = 391876592976. Its totient is φ = 130625530990.

The previous prime is 261251061943. The next prime is 261251062049. The reversal of 261251061982 is 289160152162.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 65312765494 + ... + 65312765497.

It is an arithmetic number, because the mean of its divisors is an integer number (97969148244).

Almost surely, 2^261251061982 is an apocalyptic number.

261251061982 is a deficient number, since it is larger than the sum of its proper divisors (130625530994).

261251061982 is a wasteful number, since it uses less digits than its factorization.

261251061982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130625530993.

The product of its (nonzero) digits is 103680, while the sum is 43.

The spelling of 261251061982 in words is "two hundred sixty-one billion, two hundred fifty-one million, sixty-one thousand, nine hundred eighty-two".