261231804 has 36 divisors (see below), whose sum is σ = 684795384. Its totient is φ = 87076944.

The previous prime is 261231757. The next prime is 261231811. The reversal of 261231804 is 408132162.

261231804 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133407 + ... + 135350.

It is an arithmetic number, because the mean of its divisors is an integer number (19022094).

Almost surely, 2^261231804 is an apocalyptic number.

It is an amenable number.

261231804 is an abundant number, since it is smaller than the sum of its proper divisors (423563580).

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

261231804 is a wasteful number, since it uses less digits than its factorization.

261231804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268776 (or 268762 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 261231804 is about 16162.6669828961. Note that the first 3 decimals coincide. The cubic root of 261231804 is about 639.2567902653.

Adding to 261231804 its reverse (408132162), we get a palindrome (669363966).

The spelling of 261231804 in words is "two hundred sixty-one million, two hundred thirty-one thousand, eight hundred four".