261624 has 32 divisors (see below), whose sum is σ = 714240. Its totient is φ = 79200.

The previous prime is 261619. The next prime is 261631. The reversal of 261624 is 426162.

It is a happy number.

261624 is nontrivially palindromic in base 14.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 261624.

It is a congruent number.

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, 232 + ... + 759.

It is an arithmetic number, because the mean of its divisors is an integer number (22320).

2²⁶¹⁶²⁴ is an apocalyptic number.

261624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261624 is an abundant number, since it is smaller than the sum of its proper divisors (452616).

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

261624 is a wasteful number, since it uses less digits than its factorization.

261624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1011 (or 1007 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 261624 is about 511.4919354203. The cubic root of 261624 is about 63.9576542797.

Adding to 261624 its reverse (426162), we get a palindrome (687786).

It can be divided in two parts, 26 and 1624, that multiplied together give a palindrome (42224).

The spelling of 261624 in words is "two hundred sixty-one thousand, six hundred twenty-four".