261668690325504 has 624 divisors, whose sum is σ = 943343916712704. Its totient is φ = 67893873868800.

The previous prime is 261668690325491. The next prime is 261668690325547. The reversal of 261668690325504 is 405523096866162.

261668690325504 is a `hidden beast` number, since 2 + 6 + 1 + 6 + 6 + 8 + 6 + 90 + 32 + 5 + 504 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2705068819 + ... + 2705165549.

It is an arithmetic number, because the mean of its divisors is an integer number (1511769097296).

Almost surely, 2^{261668690325504} is an apocalyptic number.

261668690325504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261668690325504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471671958356352).

261668690325504 is an abundant number, since it is smaller than the sum of its proper divisors (681675226387200).

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

261668690325504 is a wasteful number, since it uses less digits than its factorization.

261668690325504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97732 (or 97707 counting only the distinct ones).

The product of its (nonzero) digits is 111974400, while the sum is 63.

The spelling of 261668690325504 in words is "two hundred sixty-one trillion, six hundred sixty-eight billion, six hundred ninety million, three hundred twenty-five thousand, five hundred four".