261603120 has 40 divisors (see below), whose sum is σ = 810970416. Its totient is φ = 69760768.

The previous prime is 261603107. The next prime is 261603131. The reversal of 261603120 is 21306162.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 544767 + ... + 545246.

Almost surely, 2^261603120 is an apocalyptic number.

261603120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261603120 is an abundant number, since it is smaller than the sum of its proper divisors (549367296).

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

261603120 is a wasteful number, since it uses less digits than its factorization.

261603120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090029 (or 1090023 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 261603120 is about 16174.1497458135. The cubic root of 261603120 is about 639.5595276489.

Adding to 261603120 its reverse (21306162), we get a palindrome (282909282).

The spelling of 261603120 in words is "two hundred sixty-one million, six hundred three thousand, one hundred twenty".