1264665543552 has 128 divisors (see below), whose sum is σ = 3733358304000. Its totient is φ = 421460485632.

The previous prime is 1264665543521. The next prime is 1264665543569. The reversal of 1264665543552 is 2553455664621.

1264665543552 is a `hidden beast` number, since 1 + 2 + 6 + 4 + 6 + 6 + 554 + 35 + 52 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16283949 + ... + 16361427.

It is an arithmetic number, because the mean of its divisors is an integer number (29166861750).

Almost surely, 2^{1264665543552} is an apocalyptic number.

1264665543552 is a gapful number since it is divisible by the number (12) 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 1264665543552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1866679152000).

1264665543552 is an abundant number, since it is smaller than the sum of its proper divisors (2468692760448).

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

1264665543552 is an equidigital number, since it uses as much as digits as its factorization.

1264665543552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82225 (or 82207 counting only the distinct ones).

The product of its digits is 25920000, while the sum is 54.

The spelling of 1264665543552 in words is "one trillion, two hundred sixty-four billion, six hundred sixty-five million, five hundred forty-three thousand, five hundred fifty-two".