261631545460 has 24 divisors (see below), whose sum is σ = 578343417120. Its totient is φ = 99144585504.

The previous prime is 261631545451. The next prime is 261631545473. The reversal of 261631545460 is 64545136162.

261631545460 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261631545460² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344251654 + ... + 344252413.

It is an arithmetic number, because the mean of its divisors is an integer number (24097642380).

Almost surely, 2^261631545460 is an apocalyptic number.

261631545460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261631545460 is an abundant number, since it is smaller than the sum of its proper divisors (316711871660).

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

261631545460 is a wasteful number, since it uses less digits than its factorization.

261631545460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688504095 (or 688504093 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 261631545460 in words is "two hundred sixty-one billion, six hundred thirty-one million, five hundred forty-five thousand, four hundred sixty".