1670640985 has 8 divisors (see below), whose sum is σ = 2158982280. Its totient is φ = 1233704064.

The previous prime is 1670640919. The next prime is 1670640997. The reversal of 1670640985 is 5890460761.

It can be written as a sum of positive squares in 4 ways, for example, as 447561 + 1670193424 = 669^2 + 40868^2 .

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 1670640985 - 2¹⁹ = 1670116697 is a prime.

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, 12851020 + ... + 12851149.

It is an arithmetic number, because the mean of its divisors is an integer number (269872785).

Almost surely, 2^1670640985 is an apocalyptic number.

It is an amenable number.

1670640985 is a deficient number, since it is larger than the sum of its proper divisors (488341295).

1670640985 is a wasteful number, since it uses less digits than its factorization.

1670640985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25702187.

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 1670640985 is about 40873.4753232460. The cubic root of 1670640985 is about 1186.5727684806.

The spelling of 1670640985 in words is "one billion, six hundred seventy million, six hundred forty thousand, nine hundred eighty-five".