261943742788 has 48 divisors (see below), whose sum is σ = 565064456320. Its totient is φ = 103464843264.

The previous prime is 261943742773. The next prime is 261943742789. The reversal of 261943742788 is 887247349162.

It is a super-2 number, since 2×261943742788² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261943742789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 325533 + ... + 793636.

Almost surely, 2^261943742788 is an apocalyptic number.

261943742788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261943742788 is an abundant number, since it is smaller than the sum of its proper divisors (303120713532).

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

261943742788 is a wasteful number, since it uses less digits than its factorization.

261943742788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1119836 (or 1119834 counting only the distinct ones).

The product of its digits is 32514048, while the sum is 61.

The spelling of 261943742788 in words is "two hundred sixty-one billion, nine hundred forty-three million, seven hundred forty-two thousand, seven hundred eighty-eight".