1297735668 has 72 divisors (see below), whose sum is σ = 3435825120. Its totient is φ = 428263200.

The previous prime is 1297735661. The next prime is 1297735679. The reversal of 1297735668 is 8665377921.

1297735668 is a `hidden beast` number, since 1 + 2 + 9 + 7 + 73 + 566 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1297735661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91563 + ... + 104781.

Almost surely, 2^1297735668 is an apocalyptic number.

1297735668 is a gapful number since it is divisible by the number (18) 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 1297735668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1717912560).

1297735668 is an abundant number, since it is smaller than the sum of its proper divisors (2138089452).

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

1297735668 is a wasteful number, since it uses less digits than its factorization.

1297735668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13339 (or 13325 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The square root of 1297735668 is about 36024.0984342426. The cubic root of 1297735668 is about 1090.7588543336.

The spelling of 1297735668 in words is "one billion, two hundred ninety-seven million, seven hundred thirty-five thousand, six hundred sixty-eight".