261411920 has 80 divisors (see below), whose sum is σ = 757772928. Its totient is φ = 81477120.

The previous prime is 261411893. The next prime is 261411923. The reversal of 261411920 is 29114162.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 261411920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261411923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15059 + ... + 27378.

Almost surely, 2^261411920 is an apocalyptic number.

261411920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261411920 is an abundant number, since it is smaller than the sum of its proper divisors (496361008).

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

261411920 is a wasteful number, since it uses less digits than its factorization.

261411920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42468 (or 42462 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 261411920 is about 16168.2379992379. The cubic root of 261411920 is about 639.4036763154.

The spelling of 261411920 in words is "two hundred sixty-one million, four hundred eleven thousand, nine hundred twenty".