1268631640 has 32 divisors (see below), whose sum is σ = 2901220560. Its totient is φ = 499132800.

The previous prime is 1268631619. The next prime is 1268631649. The reversal of 1268631640 is 461368621.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1268631640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1268631649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257526 + ... + 262405.

Almost surely, 2^1268631640 is an apocalyptic number.

1268631640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1268631640 is an abundant number, since it is smaller than the sum of its proper divisors (1632588920).

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

1268631640 is a wasteful number, since it uses less digits than its factorization.

1268631640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520003 (or 519999 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 1268631640 is about 35617.8556344988. The cubic root of 1268631640 is about 1082.5430584134.

The spelling of 1268631640 in words is "one billion, two hundred sixty-eight million, six hundred thirty-one thousand, six hundred forty".