261298644 has 12 divisors (see below), whose sum is σ = 609696864. Its totient is φ = 87099544.

The previous prime is 261298643. The next prime is 261298649. The reversal of 261298644 is 446892162.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 261298596 and 261298605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261298643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10887432 + ... + 10887455.

It is an arithmetic number, because the mean of its divisors is an integer number (50808072).

Almost surely, 2^261298644 is an apocalyptic number.

It is an amenable number.

261298644 is an abundant number, since it is smaller than the sum of its proper divisors (348398220).

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

261298644 is a wasteful number, since it uses less digits than its factorization.

261298644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21774894 (or 21774892 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 261298644 is about 16164.7345787056. The cubic root of 261298644 is about 639.3113067005.

The spelling of 261298644 in words is "two hundred sixty-one million, two hundred ninety-eight thousand, six hundred forty-four".