261964538326 has 4 divisors (see below), whose sum is σ = 392946807492. Its totient is φ = 130982269162.

The previous prime is 261964538299. The next prime is 261964538333. The reversal of 261964538326 is 623835469162.

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, 65491134580 + ... + 65491134583.

It is an arithmetic number, because the mean of its divisors is an integer number (98236701873).

Almost surely, 2^261964538326 is an apocalyptic number.

261964538326 is a deficient number, since it is larger than the sum of its proper divisors (130982269166).

261964538326 is a wasteful number, since it uses less digits than its factorization.

261964538326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130982269165.

The product of its digits is 11197440, while the sum is 55.

The spelling of 261964538326 in words is "two hundred sixty-one billion, nine hundred sixty-four million, five hundred thirty-eight thousand, three hundred twenty-six".