261057220 has 12 divisors (see below), whose sum is σ = 548220204. Its totient is φ = 104422880.

The previous prime is 261057179. The next prime is 261057221. The reversal of 261057220 is 22750162.

It can be written as a sum of positive squares in 2 ways, for example, as 125753796 + 135303424 = 11214^2 + 11632^2 .

It is a super-2 number, since 2×261057220² = 136301744228256800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261057221) 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, 6526411 + ... + 6526450.

It is an arithmetic number, because the mean of its divisors is an integer number (45685017).

Almost surely, 2^261057220 is an apocalyptic number.

261057220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261057220 is an abundant number, since it is smaller than the sum of its proper divisors (287162984).

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

261057220 is a wasteful number, since it uses less digits than its factorization.

261057220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13052870 (or 13052868 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 261057220 is about 16157.2652388949. The cubic root of 261057220 is about 639.1143511530.

The spelling of 261057220 in words is "two hundred sixty-one million, fifty-seven thousand, two hundred twenty".