261385646 has 8 divisors (see below), whose sum is σ = 392985264. Its totient is φ = 130390560.

The previous prime is 261385637. The next prime is 261385651. The reversal of 261385646 is 646583162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150050 + ... + 151781.

It is an arithmetic number, because the mean of its divisors is an integer number (49123158).

Almost surely, 2^261385646 is an apocalyptic number.

261385646 is a deficient number, since it is larger than the sum of its proper divisors (131599618).

261385646 is a wasteful number, since it uses less digits than its factorization.

261385646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302266.

The product of its digits is 207360, while the sum is 41.

The square root of 261385646 is about 16167.4254598560. The cubic root of 261385646 is about 639.3822538607.

The spelling of 261385646 in words is "two hundred sixty-one million, three hundred eighty-five thousand, six hundred forty-six".