261212740 has 12 divisors (see below), whose sum is σ = 548546796. Its totient is φ = 104485088.

The previous prime is 261212737. The next prime is 261212767. The reversal of 261212740 is 47212162.

It can be written as a sum of positive squares in 2 ways, for example, as 200279104 + 60933636 = 14152^2 + 7806^2 .

It is an unprimeable number.

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, 6530299 + ... + 6530338.

It is an arithmetic number, because the mean of its divisors is an integer number (45712233).

Almost surely, 2^261212740 is an apocalyptic number.

261212740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261212740 is an abundant number, since it is smaller than the sum of its proper divisors (287334056).

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

261212740 is a wasteful number, since it uses less digits than its factorization.

261212740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13060646 (or 13060644 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 261212740 is about 16162.0772179816. The cubic root of 261212740 is about 639.2412394687.

The spelling of 261212740 in words is "two hundred sixty-one million, two hundred twelve thousand, seven hundred forty".