1261420511104 has 256 divisors, whose sum is σ = 2979484300800. Its totient is φ = 526348247040.

The previous prime is 1261420511083. The next prime is 1261420511147. The reversal of 1261420511104 is 4011150241621.

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 31 ways as a sum of consecutive naturals, for example, 357037722 + ... + 357041254.

It is an arithmetic number, because the mean of its divisors is an integer number (11638610550).

Almost surely, 2^{1261420511104} 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 1261420511104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1489742150400).

1261420511104 is an abundant number, since it is smaller than the sum of its proper divisors (1718063789696).

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

1261420511104 is a wasteful number, since it uses less digits than its factorization.

1261420511104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4093 (or 4081 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

Adding to 1261420511104 its reverse (4011150241621), we get a palindrome (5272570752725).

The spelling of 1261420511104 in words is "one trillion, two hundred sixty-one billion, four hundred twenty million, five hundred eleven thousand, one hundred four".