261434440 has 16 divisors (see below), whose sum is σ = 588227580. Its totient is φ = 104573760.

The previous prime is 261434419. The next prime is 261434441. The reversal of 261434440 is 44434162.

It can be written as a sum of positive squares in 2 ways, for example, as 248945284 + 12489156 = 15778^2 + 3534^2 .

It is a super-2 number, since 2×261434440² = 136695932836227200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261434399 and 261434408.

It is not an unprimeable number, because it can be changed into a prime (261434441) 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 3 ways as a sum of consecutive naturals, for example, 3267891 + ... + 3267970.

Almost surely, 2^261434440 is an apocalyptic number.

261434440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261434440 is an abundant number, since it is smaller than the sum of its proper divisors (326793140).

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

261434440 is a wasteful number, since it uses less digits than its factorization.

261434440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6535872 (or 6535868 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 261434440 is about 16168.9344113952. The cubic root of 261434440 is about 639.4220368111.

The spelling of 261434440 in words is "two hundred sixty-one million, four hundred thirty-four thousand, four hundred forty".