261603144 has 96 divisors (see below), whose sum is σ = 778883040. Its totient is φ = 78662400.

The previous prime is 261603137. The next prime is 261603149. The reversal of 261603144 is 441306162.

261603144 is a `hidden beast` number, since 2 + 616 + 0 + 3 + 1 + 44 = 666.

It is not an unprimeable number, because it can be changed into a prime (261603149) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 107299 + ... + 109709.

It is an arithmetic number, because the mean of its divisors is an integer number (8113365).

Almost surely, 2^261603144 is an apocalyptic number.

261603144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261603144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (389441520).

261603144 is an abundant number, since it is smaller than the sum of its proper divisors (517279896).

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

261603144 is a wasteful number, since it uses less digits than its factorization.

261603144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2571 (or 2564 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 261603144 is about 16174.1504877381. The cubic root of 261603144 is about 639.5595472070.

The spelling of 261603144 in words is "two hundred sixty-one million, six hundred three thousand, one hundred forty-four".