261489764 has 12 divisors (see below), whose sum is σ = 467343744. Its totient is φ = 127962984.

The previous prime is 261489749. The next prime is 261489773. The reversal of 261489764 is 467984162.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 695264 + ... + 695639.

It is an arithmetic number, because the mean of its divisors is an integer number (38945312).

Almost surely, 2^261489764 is an apocalyptic number.

It is an amenable number.

261489764 is a deficient number, since it is larger than the sum of its proper divisors (205853980).

261489764 is a wasteful number, since it uses less digits than its factorization.

261489764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1390954 (or 1390952 counting only the distinct ones).

The product of its digits is 580608, while the sum is 47.

The square root of 261489764 is about 16170.6451324615. The cubic root of 261489764 is about 639.4671378438.

The spelling of 261489764 in words is "two hundred sixty-one million, four hundred eighty-nine thousand, seven hundred sixty-four".