1261515280064 has 168 divisors, whose sum is σ = 2860154594640. Its totient is φ = 550281019392.

The previous prime is 1261515280049. The next prime is 1261515280073. The reversal of 1261515280064 is 4600825151621.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88976144 + ... + 88990320.

It is an arithmetic number, because the mean of its divisors is an integer number (17024729730).

Almost surely, 2^{1261515280064} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261515280064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1430077297320).

1261515280064 is an abundant number, since it is smaller than the sum of its proper divisors (1598639314576).

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

1261515280064 is a wasteful number, since it uses less digits than its factorization.

1261515280064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14667 (or 14644 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 41.

The spelling of 1261515280064 in words is "one trillion, two hundred sixty-one billion, five hundred fifteen million, two hundred eighty thousand, sixty-four".