670021640 has 16 divisors (see below), whose sum is σ = 1507548780. Its totient is φ = 268008640.

The previous prime is 670021619. The next prime is 670021687. The reversal of 670021640 is 46120076.

It can be written as a sum of positive squares in 2 ways, for example, as 635140804 + 34880836 = 25202^2 + 5906^2 .

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, 8375231 + ... + 8375310.

Almost surely, 2^670021640 is an apocalyptic number.

It is an amenable number.

670021640 is an abundant number, since it is smaller than the sum of its proper divisors (837527140).

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

670021640 is a wasteful number, since it uses less digits than its factorization.

670021640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16750552 (or 16750548 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 670021640 is about 25884.7762207827. The cubic root of 670021640 is about 875.0434329461.

The spelling of 670021640 in words is "six hundred seventy million, twenty-one thousand, six hundred forty".