261929913 has 32 divisors (see below), whose sum is σ = 411378432. Its totient is φ = 145152000.

The previous prime is 261929903. The next prime is 261929929. The reversal of 261929913 is 319929162.

It is not a de Polignac number, because 261929913 - 2⁶ = 261929849 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (261929903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92113 + ... + 94913.

It is an arithmetic number, because the mean of its divisors is an integer number (12855576).

Almost surely, 2^261929913 is an apocalyptic number.

It is an amenable number.

261929913 is a deficient number, since it is larger than the sum of its proper divisors (149448519).

261929913 is a wasteful number, since it uses less digits than its factorization.

261929913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2945.

The product of its digits is 52488, while the sum is 42.

The square root of 261929913 is about 16184.2489167709. The cubic root of 261929913 is about 639.8257281035.

The spelling of 261929913 in words is "two hundred sixty-one million, nine hundred twenty-nine thousand, nine hundred thirteen".