261623604 has 24 divisors (see below), whose sum is σ = 665951328. Its totient is φ = 79279840.

The previous prime is 261623603. The next prime is 261623623. The reversal of 261623604 is 406326162.

261623604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261623603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 990867 + ... + 991130.

It is an arithmetic number, because the mean of its divisors is an integer number (27747972).

Almost surely, 2^261623604 is an apocalyptic number.

It is an amenable number.

261623604 is an abundant number, since it is smaller than the sum of its proper divisors (404327724).

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

261623604 is a wasteful number, since it uses less digits than its factorization.

261623604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1982015 (or 1982013 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 261623604 is about 16174.7829660864. The cubic root of 261623604 is about 639.5762201045.

Adding to 261623604 its reverse (406326162), we get a palindrome (667949766).

The spelling of 261623604 in words is "two hundred sixty-one million, six hundred twenty-three thousand, six hundred four".