646473986 has 8 divisors (see below), whose sum is σ = 978607740. Its totient is φ = 320271408.

The previous prime is 646473983. The next prime is 646474007. The reversal of 646473986 is 689374646.

It can be written as a sum of positive squares in 2 ways, for example, as 623251225 + 23222761 = 24965^2 + 4819^2 .

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

It is a super-2 number, since 2×646473986² = 835857229149456392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646473983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1482521 + ... + 1482956.

Almost surely, 2^646473986 is an apocalyptic number.

646473986 is a deficient number, since it is larger than the sum of its proper divisors (332133754).

646473986 is a wasteful number, since it uses less digits than its factorization.

646473986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2965588.

The product of its digits is 5225472, while the sum is 53.

The square root of 646473986 is about 25425.8527093980. The cubic root of 646473986 is about 864.6699202797.

The spelling of 646473986 in words is "six hundred forty-six million, four hundred seventy-three thousand, nine hundred eighty-six".