1285944660 has 720 divisors, whose sum is σ = 5535395712. Its totient is φ = 242611200.

The previous prime is 1285944619. The next prime is 1285944661. The reversal of 1285944660 is 664495821.

1285944660 is a `hidden beast` number, since 12 + 8 + 594 + 46 + 6 + 0 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1285944661) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 21081030 + ... + 21081090.

Almost surely, 2^1285944660 is an apocalyptic number.

1285944660 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 1285944660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2767697856).

1285944660 is an abundant number, since it is smaller than the sum of its proper divisors (4249451052).

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

1285944660 is a wasteful number, since it uses less digits than its factorization.

1285944660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 1285944660 is about 35860.0705520778. The cubic root of 1285944660 is about 1087.4453147294.

The spelling of 1285944660 in words is "one billion, two hundred eighty-five million, nine hundred forty-four thousand, six hundred sixty".