261165624 has 64 divisors (see below), whose sum is σ = 668304000. Its totient is φ = 85023360.

The previous prime is 261165623. The next prime is 261165629. The reversal of 261165624 is 426561162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261165623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255787 + ... + 256805.

It is an arithmetic number, because the mean of its divisors is an integer number (10442250).

Almost surely, 2^261165624 is an apocalyptic number.

261165624 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 261165624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334152000).

261165624 is an abundant number, since it is smaller than the sum of its proper divisors (407138376).

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

261165624 is a wasteful number, since it uses less digits than its factorization.

261165624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1268 (or 1264 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 261165624 is about 16160.6195425794. The cubic root of 261165624 is about 639.2028029804.

The spelling of 261165624 in words is "two hundred sixty-one million, one hundred sixty-five thousand, six hundred twenty-four".