1266641640 has 192 divisors, whose sum is σ = 4506840000. Its totient is φ = 305971200.

The previous prime is 1266641639. The next prime is 1266641653. The reversal of 1266641640 is 461466621.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1266641595 and 1266641604.

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 47 ways as a sum of consecutive naturals, for example, 1975720 + ... + 1976360.

It is an arithmetic number, because the mean of its divisors is an integer number (23473125).

Almost surely, 2^1266641640 is an apocalyptic number.

1266641640 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 1266641640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2253420000).

1266641640 is an abundant number, since it is smaller than the sum of its proper divisors (3240198360).

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

1266641640 is a wasteful number, since it uses less digits than its factorization.

1266641640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1168 (or 1161 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 1266641640 is about 35589.9092440540. The cubic root of 1266641640 is about 1081.9767295686.

The spelling of 1266641640 in words is "one billion, two hundred sixty-six million, six hundred forty-one thousand, six hundred forty".