261420 has 24 divisors (see below), whose sum is σ = 732144. Its totient is φ = 69696.

The previous prime is 261407. The next prime is 261427. The reversal of 261420 is 24162.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 261420.

It is not an unprimeable number, because it can be changed into a prime (261427) by changing a digit.

261420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2119 + ... + 2238.

It is an arithmetic number, because the mean of its divisors is an integer number (30506).

2²⁶¹⁴²⁰ is an apocalyptic number.

261420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261420 is an abundant number, since it is smaller than the sum of its proper divisors (470724).

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

261420 is a wasteful number, since it uses less digits than its factorization.

261420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4369 (or 4367 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 261420 is about 511.2924798978. The cubic root of 261420 is about 63.9410264039.

Adding to 261420 its reverse (24162), we get a palindrome (285582).

The spelling of 261420 in words is "two hundred sixty-one thousand, four hundred twenty".