1664630986 has 4 divisors (see below), whose sum is σ = 2496946482. Its totient is φ = 832315492.

The previous prime is 1664630977. The next prime is 1664631011. The reversal of 1664630986 is 6890364661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1656897025 + 7733961 = 40705^2 + 2781^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416157745 + ... + 416157748.

Almost surely, 2^1664630986 is an apocalyptic number.

1664630986 is a deficient number, since it is larger than the sum of its proper divisors (832315496).

1664630986 is an equidigital number, since it uses as much as digits as its factorization.

1664630986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832315495.

The product of its (nonzero) digits is 1119744, while the sum is 49.

The square root of 1664630986 is about 40799.8895341642. The cubic root of 1664630986 is about 1185.1481915710.

The spelling of 1664630986 in words is "one billion, six hundred sixty-four million, six hundred thirty thousand, nine hundred eighty-six".