646478166 has 16 divisors (see below), whose sum is σ = 1299456000. Its totient is φ = 214409448.

The previous prime is 646478149. The next prime is 646478167. The reversal of 646478166 is 661874646.

It is a super-2 number, since 2×646478166² = 835868038229447112, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646478167) 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, 269526 + ... + 271913.

It is an arithmetic number, because the mean of its divisors is an integer number (81216000).

Almost surely, 2^646478166 is an apocalyptic number.

646478166 is an abundant number, since it is smaller than the sum of its proper divisors (652977834).

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

646478166 is a wasteful number, since it uses less digits than its factorization.

646478166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541643.

The product of its digits is 1161216, while the sum is 48.

The square root of 646478166 is about 25425.9349090648. The cubic root of 646478166 is about 864.6717838827.

The spelling of 646478166 in words is "six hundred forty-six million, four hundred seventy-eight thousand, one hundred sixty-six".