261945592840 has 16 divisors (see below), whose sum is σ = 589377583980. Its totient is φ = 104778237120.

The previous prime is 261945592817. The next prime is 261945592841. The reversal of 261945592840 is 48295549162.

It can be written as a sum of positive squares in 2 ways, for example, as 248145452164 + 13800140676 = 498142^2 + 117474^2 .

It is not an unprimeable number, because it can be changed into a prime (261945592841) 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, 3274319871 + ... + 3274319950.

Almost surely, 2^261945592840 is an apocalyptic number.

261945592840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261945592840 is an abundant number, since it is smaller than the sum of its proper divisors (327431991140).

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

261945592840 is a wasteful number, since it uses less digits than its factorization.

261945592840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6548639832 (or 6548639828 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 55.

The spelling of 261945592840 in words is "two hundred sixty-one billion, nine hundred forty-five million, five hundred ninety-two thousand, eight hundred forty".