64509866 has 16 divisors (see below), whose sum is σ = 102612744. Its totient is φ = 30311424.

The previous prime is 64509859. The next prime is 64509877. The reversal of 64509866 is 66890546.

It can be written as a sum of positive squares in 4 ways, for example, as 23280625 + 41229241 = 4825^2 + 6421^2 .

It is a super-2 number, since 2×64509866² = 8323045622675912, which contains 22 as substring.

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, 33506 + ... + 35378.

Almost surely, 2^64509866 is an apocalyptic number.

64509866 is a deficient number, since it is larger than the sum of its proper divisors (38102878).

64509866 is a wasteful number, since it uses less digits than its factorization.

64509866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2905.

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 64509866 is about 8031.8034089487. The cubic root of 64509866 is about 401.0594124692.

The spelling of 64509866 in words is "sixty-four million, five hundred nine thousand, eight hundred sixty-six".