261534370137220 has 24 divisors (see below), whose sum is σ = 549244753104600. Its totient is φ = 104609447899392.

The previous prime is 261534370137151. The next prime is 261534370137239. The reversal of 261534370137220 is 22731073435162.

It can be written as a sum of positive squares in 4 ways, for example, as 56452952736324 + 205081417400896 = 7513518^2 + 14320664^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 268260975 + ... + 269234134.

It is an arithmetic number, because the mean of its divisors is an integer number (22885198046025).

Almost surely, 2^{261534370137220} is an apocalyptic number.

261534370137220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261534370137220 is an abundant number, since it is smaller than the sum of its proper divisors (287710382967380).

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

261534370137220 is a wasteful number, since it uses less digits than its factorization.

261534370137220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537519447 (or 537519445 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 46.

The spelling of 261534370137220 in words is "two hundred sixty-one trillion, five hundred thirty-four billion, three hundred seventy million, one hundred thirty-seven thousand, two hundred twenty".