261488128000 has 416 divisors, whose sum is σ = 736930509120. Its totient is φ = 91750400000.

The previous prime is 261488127991. The next prime is 261488128001. The reversal of 261488128000 is 821884162.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (261488128001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163327200 + ... + 163328800.

It is an arithmetic number, because the mean of its divisors is an integer number (1771467570).

Almost surely, 2^261488128000 is an apocalyptic number.

261488128000 is a gapful number since it is divisible by the number (20) 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 261488128000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (368465254560).

261488128000 is an abundant number, since it is smaller than the sum of its proper divisors (475442381120).

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

261488128000 is a wasteful number, since it uses less digits than its factorization.

261488128000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1680 (or 1648 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 40.

The spelling of 261488128000 in words is "two hundred sixty-one billion, four hundred eighty-eight million, one hundred twenty-eight thousand".