261523404 has 36 divisors (see below), whose sum is σ = 685559784. Its totient is φ = 87174144.

The previous prime is 261523403. The next prime is 261523411. The reversal of 261523404 is 404325162.

261523404 is a `hidden beast` number, since 2 + 615 + 2 + 3 + 40 + 4 = 666.

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 not an unprimeable number, because it can be changed into a prime (261523403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133557 + ... + 135500.

Almost surely, 2^261523404 is an apocalyptic number.

It is an amenable number.

261523404 is an abundant number, since it is smaller than the sum of its proper divisors (424036380).

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

261523404 is a wasteful number, since it uses less digits than its factorization.

261523404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269076 (or 269062 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 261523404 is about 16171.6852554086. The cubic root of 261523404 is about 639.4945586139.

Adding to 261523404 its reverse (404325162), we get a palindrome (665848566).

The spelling of 261523404 in words is "two hundred sixty-one million, five hundred twenty-three thousand, four hundred four".