261345604 has 36 divisors (see below), whose sum is σ = 500071852. Its totient is φ = 118802880.

The previous prime is 261345599. The next prime is 261345629. The reversal of 261345604 is 406543162.

261345604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 132296004 + 129049600 = 11502^2 + 11360^2 .

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, 261634 + ... + 262630.

Almost surely, 2^261345604 is an apocalyptic number.

It is an amenable number.

261345604 is a deficient number, since it is larger than the sum of its proper divisors (238726248).

261345604 is a wasteful number, since it uses less digits than its factorization.

261345604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1156 (or 1083 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 261345604 is about 16166.1870581779. The cubic root of 261345604 is about 639.3496029327.

Adding to 261345604 its reverse (406543162), we get a palindrome (667888766).

The spelling of 261345604 in words is "two hundred sixty-one million, three hundred forty-five thousand, six hundred four".