1680988621 has 8 divisors (see below), whose sum is σ = 1819395200. Its totient is φ = 1543882032.

The previous prime is 1680988613. The next prime is 1680988633. The reversal of 1680988621 is 1268890861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1680988621 - 2³ = 1680988613 is a prime.

It is a super-3 number, since 3×1680988621³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680988601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 322305 + ... + 327478.

It is an arithmetic number, because the mean of its divisors is an integer number (227424400).

Almost surely, 2^1680988621 is an apocalyptic number.

It is an amenable number.

1680988621 is a deficient number, since it is larger than the sum of its proper divisors (138406579).

1680988621 is a wasteful number, since it uses less digits than its factorization.

1680988621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649995.

The product of its (nonzero) digits is 331776, while the sum is 49.

The square root of 1680988621 is about 40999.8612314725. The cubic root of 1680988621 is about 1189.0175307819.

The spelling of 1680988621 in words is "one billion, six hundred eighty million, nine hundred eighty-eight thousand, six hundred twenty-one".