261204506 has 4 divisors (see below), whose sum is σ = 391806762. Its totient is φ = 130602252.

The previous prime is 261204443. The next prime is 261204523. The reversal of 261204506 is 605402162.

261204506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 227738281 + 33466225 = 15091^2 + 5785^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65301125 + ... + 65301128.

Almost surely, 2^261204506 is an apocalyptic number.

261204506 is a deficient number, since it is larger than the sum of its proper divisors (130602256).

261204506 is a wasteful number, since it uses less digits than its factorization.

261204506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130602255.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 261204506 is about 16161.8224838661. The cubic root of 261204506 is about 639.2345226349.

Adding to 261204506 its reverse (605402162), we get a palindrome (866606668).

The spelling of 261204506 in words is "two hundred sixty-one million, two hundred four thousand, five hundred six".