261394840 has 32 divisors (see below), whose sum is σ = 672158880. Its totient is φ = 89620992.

The previous prime is 261394831. The next prime is 261394849. The reversal of 261394840 is 48493162.

It is an interprime number because it is at equal distance from previous prime (261394831) and next prime (261394849).

It is a self number, because there is not a number n which added to its sum of digits gives 261394840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261394849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 466497 + ... + 467056.

It is an arithmetic number, because the mean of its divisors is an integer number (21004965).

Almost surely, 2^261394840 is an apocalyptic number.

261394840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261394840 is an abundant number, since it is smaller than the sum of its proper divisors (410764040).

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

261394840 is a wasteful number, since it uses less digits than its factorization.

261394840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933571 (or 933567 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 261394840 is about 16167.7097945256. The cubic root of 261394840 is about 639.3897503339.

The spelling of 261394840 in words is "two hundred sixty-one million, three hundred ninety-four thousand, eight hundred forty".