261534735620 has 24 divisors (see below), whose sum is σ = 549232719000. Its totient is φ = 104612032512.

The previous prime is 261534735617. The next prime is 261534735659. The reversal of 261534735620 is 26537435162.

It can be written as a sum of positive squares in 4 ways, for example, as 18059596996 + 243475138624 = 134386^2 + 493432^2 .

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, 1828046 + ... + 1965914.

It is an arithmetic number, because the mean of its divisors is an integer number (22884696625).

Almost surely, 2^261534735620 is an apocalyptic number.

261534735620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261534735620 is an abundant number, since it is smaller than the sum of its proper divisors (287697983380).

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

261534735620 is a wasteful number, since it uses less digits than its factorization.

261534735620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232727 (or 232725 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 44.

The spelling of 261534735620 in words is "two hundred sixty-one billion, five hundred thirty-four million, seven hundred thirty-five thousand, six hundred twenty".