1681617601644 has 24 divisors (see below), whose sum is σ = 3925876102848. Its totient is φ = 560238957840.

The previous prime is 1681617601627. The next prime is 1681617601669. The reversal of 1681617601644 is 4461067161861.

It is a happy 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, 37507002 + ... + 37551809.

It is an arithmetic number, because the mean of its divisors is an integer number (163578170952).

Almost surely, 2^{1681617601644} is an apocalyptic number.

It is an amenable number.

1681617601644 is an abundant number, since it is smaller than the sum of its proper divisors (2244258501204).

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

1681617601644 is a wasteful number, since it uses less digits than its factorization.

1681617601644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75060685 (or 75060683 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 51.

The spelling of 1681617601644 in words is "one trillion, six hundred eighty-one billion, six hundred seventeen million, six hundred one thousand, six hundred forty-four".