1993987190640 has 80 divisors (see below), whose sum is σ = 6380759033856. Its totient is φ = 514577337600.

The previous prime is 1993987190621. The next prime is 1993987190651. The reversal of 1993987190640 is 460917893991.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133997076 + ... + 134011955.

Almost surely, 2^{1993987190640} is an apocalyptic number.

1993987190640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1993987190640 is an abundant number, since it is smaller than the sum of its proper divisors (4386771843216).

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

1993987190640 is a wasteful number, since it uses less digits than its factorization.

1993987190640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268009078 (or 268009072 counting only the distinct ones).

The product of its (nonzero) digits is 26453952, while the sum is 66.

The spelling of 1993987190640 in words is "one trillion, nine hundred ninety-three billion, nine hundred eighty-seven million, one hundred ninety thousand, six hundred forty".