261993375 has 192 divisors, whose sum is σ = 607426560. Its totient is φ = 105753600.

The previous prime is 261993373. The next prime is 261993377. The reversal of 261993375 is 573399162.

It is an interprime number because it is at equal distance from previous prime (261993373) and next prime (261993377).

It is not a de Polignac number, because 261993375 - 2¹ = 261993373 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 261993375.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261993371) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2543574 + ... + 2543676.

It is an arithmetic number, because the mean of its divisors is an integer number (3163680).

Almost surely, 2^261993375 is an apocalyptic number.

261993375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

261993375 is an abundant number, since it is smaller than the sum of its proper divisors (345433185).

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

261993375 is a wasteful number, since it uses less digits than its factorization.

261993375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 154 counting only the distinct ones).

The product of its digits is 306180, while the sum is 45.

The square root of 261993375 is about 16186.2094080115. The cubic root of 261993375 is about 639.8773975762.

The spelling of 261993375 in words is "two hundred sixty-one million, nine hundred ninety-three thousand, three hundred seventy-five".