261421875 has 126 divisors (see below), whose sum is σ = 557570988. Its totient is φ = 117000000.

The previous prime is 261421829. The next prime is 261421877. The reversal of 261421875 is 578124162.

It is not a de Polignac number, because 261421875 - 2¹³ = 261413683 is a prime.

Its product of digits (26880) is a multiple of the sum of its prime divisors (32).

It is not an unprimeable number, because it can be changed into a prime (261421877) by changing a digit.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 20109369 + ... + 20109381.

Almost surely, 2^261421875 is an apocalyptic number.

261421875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

261421875 is an abundant number, since it is smaller than the sum of its proper divisors (296149113).

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

261421875 is an equidigital number, since it uses as much as digits as its factorization.

261421875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 32 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 261421875 is about 16168.5458529826. The cubic root of 261421875 is about 639.4117927303.

The spelling of 261421875 in words is "two hundred sixty-one million, four hundred twenty-one thousand, eight hundred seventy-five".