1265421618336 has 96 divisors (see below), whose sum is σ = 3469859745408. Its totient is φ = 403036508160.

The previous prime is 1265421618289. The next prime is 1265421618337. The reversal of 1265421618336 is 6338161245621.

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (1265421618337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1763076 + ... + 2374716.

It is an arithmetic number, because the mean of its divisors is an integer number (36144372348).

Almost surely, 2^{1265421618336} is an apocalyptic number.

1265421618336 is a gapful number since it is divisible by the number (16) 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 1265421618336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1734929872704).

1265421618336 is an abundant number, since it is smaller than the sum of its proper divisors (2204438127072).

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

1265421618336 is a wasteful number, since it uses less digits than its factorization.

1265421618336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612614 (or 612606 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 48.

The spelling of 1265421618336 in words is "one trillion, two hundred sixty-five billion, four hundred twenty-one million, six hundred eighteen thousand, three hundred thirty-six".