261620 has 24 divisors (see below), whose sum is σ = 559104. Its totient is φ = 102816.

The previous prime is 261619. The next prime is 261631. The reversal of 261620 is 26162.

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, 1997 + ... + 2123.

It is an arithmetic number, because the mean of its divisors is an integer number (23296).

2²⁶¹⁶²⁰ is an apocalyptic number.

261620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261620 is an abundant number, since it is smaller than the sum of its proper divisors (297484).

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

261620 is a wasteful number, since it uses less digits than its factorization.

261620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 261620 is about 511.4880252753. The cubic root of 261620 is about 63.9573283260.

Adding to 261620 its reverse (26162), we get a palindrome (287782).

The spelling of 261620 in words is "two hundred sixty-one thousand, six hundred twenty".