261740540 has 12 divisors (see below), whose sum is σ = 549655176. Its totient is φ = 104696208.

The previous prime is 261740539. The next prime is 261740543. The reversal of 261740540 is 45047162.

It is a super-2 number, since 2×261740540² = 137016220558983200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261740543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6543494 + ... + 6543533.

It is an arithmetic number, because the mean of its divisors is an integer number (45804598).

Almost surely, 2^261740540 is an apocalyptic number.

261740540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261740540 is an abundant number, since it is smaller than the sum of its proper divisors (287914636).

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

261740540 is a wasteful number, since it uses less digits than its factorization.

261740540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13087036 (or 13087034 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 261740540 is about 16178.3973248279. The cubic root of 261740540 is about 639.6714948221.

The spelling of 261740540 in words is "two hundred sixty-one million, seven hundred forty thousand, five hundred forty".