1681681212564 has 12 divisors (see below), whose sum is σ = 3923922829344. Its totient is φ = 560560404184.

The previous prime is 1681681212529. The next prime is 1681681212647. The reversal of 1681681212564 is 4652121861861.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70070050512 + ... + 70070050535.

It is an arithmetic number, because the mean of its divisors is an integer number (326993569112).

Almost surely, 2^{1681681212564} is an apocalyptic number.

It is an amenable number.

1681681212564 is an abundant number, since it is smaller than the sum of its proper divisors (2242241616780).

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

1681681212564 is a wasteful number, since it uses less digits than its factorization.

1681681212564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140140101054 (or 140140101052 counting only the distinct ones).

The product of its digits is 1105920, while the sum is 51.

The spelling of 1681681212564 in words is "one trillion, six hundred eighty-one billion, six hundred eighty-one million, two hundred twelve thousand, five hundred sixty-four".