668400253490 has 64 divisors (see below), whose sum is σ = 1343850963840. Its totient is φ = 237871549440.

The previous prime is 668400253481. The next prime is 668400253517. The reversal of 668400253490 is 94352004866.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1264589 + ... + 1713471.

It is an arithmetic number, because the mean of its divisors is an integer number (20997671310).

Almost surely, 2^668400253490 is an apocalyptic number.

668400253490 is an abundant number, since it is smaller than the sum of its proper divisors (675450710350).

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

668400253490 is a wasteful number, since it uses less digits than its factorization.

668400253490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449387.

The product of its (nonzero) digits is 1244160, while the sum is 47.

The spelling of 668400253490 in words is "six hundred sixty-eight billion, four hundred million, two hundred fifty-three thousand, four hundred ninety".