1681993881654 has 16 divisors (see below), whose sum is σ = 3370675617792. Its totient is φ = 559549984808.

The previous prime is 1681993881643. The next prime is 1681993881671. The reversal of 1681993881654 is 4561883991861.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 278657334 + ... + 278663369.

It is an arithmetic number, because the mean of its divisors is an integer number (210667226112).

Almost surely, 2^{1681993881654} is an apocalyptic number.

1681993881654 is an abundant number, since it is smaller than the sum of its proper divisors (1688681736138).

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

1681993881654 is a wasteful number, since it uses less digits than its factorization.

1681993881654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557321211.

The product of its digits is 89579520, while the sum is 69.

The spelling of 1681993881654 in words is "one trillion, six hundred eighty-one billion, nine hundred ninety-three million, eight hundred eighty-one thousand, six hundred fifty-four".