64665390 has 16 divisors (see below), whose sum is σ = 155197008. Its totient is φ = 17244096.

The previous prime is 64665347. The next prime is 64665407. The reversal of 64665390 is 9356646.

It is a happy number.

It is a super-2 number, since 2×64665390² = 8363225327704200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1077727 + ... + 1077786.

It is an arithmetic number, because the mean of its divisors is an integer number (9699813).

Almost surely, 2^64665390 is an apocalyptic number.

64665390 is an abundant number, since it is smaller than the sum of its proper divisors (90531618).

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

64665390 is a wasteful number, since it uses less digits than its factorization.

64665390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2155523.

The product of its (nonzero) digits is 116640, while the sum is 39.

The square root of 64665390 is about 8041.4793415142. The cubic root of 64665390 is about 401.3814526457.

The spelling of 64665390 in words is "sixty-four million, six hundred sixty-five thousand, three hundred ninety".