1266494021520 has 640 divisors, whose sum is σ = 5100540211200. Its totient is φ = 252453003264.

The previous prime is 1266494021497. The next prime is 1266494021521. The reversal of 1266494021520 is 251204946621.

It is a super-2 number, since 2×1266494021520² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (1266494021521) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 157265814 + ... + 157273866.

It is an arithmetic number, because the mean of its divisors is an integer number (7969594080).

Almost surely, 2^{1266494021520} is an apocalyptic number.

1266494021520 is a gapful number since it is divisible by the number (10) 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 1266494021520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2550270105600).

1266494021520 is an abundant number, since it is smaller than the sum of its proper divisors (3834046189680).

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

1266494021520 is a wasteful number, since it uses less digits than its factorization.

1266494021520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8487 (or 8481 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 42.

The spelling of 1266494021520 in words is "one trillion, two hundred sixty-six billion, four hundred ninety-four million, twenty-one thousand, five hundred twenty".