261623666656470 has 64 divisors (see below), whose sum is σ = 661943916207360. Its totient is φ = 65994408374400.

The previous prime is 261623666656379. The next prime is 261623666656483. The reversal of 261623666656470 is 74656666326162.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 346816036 + ... + 347569575.

It is an arithmetic number, because the mean of its divisors is an integer number (10342873690740).

Almost surely, 2^{261623666656470} is an apocalyptic number.

261623666656470 is an abundant number, since it is smaller than the sum of its proper divisors (400320249550890).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261623666656470 is a wasteful number, since it uses less digits than its factorization.

261623666656470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694386301.

The product of its (nonzero) digits is 470292480, while the sum is 66.

The spelling of 261623666656470 in words is "two hundred sixty-one trillion, six hundred twenty-three billion, six hundred sixty-six million, six hundred fifty-six thousand, four hundred seventy".