64438390 has 8 divisors (see below), whose sum is σ = 115989120. Its totient is φ = 25775352.

The previous prime is 64438369. The next prime is 64438417. The reversal of 64438390 is 9383446.

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

It is a super-2 number, since 2×64438390² = 8304612211584200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3221910 + ... + 3221929.

It is an arithmetic number, because the mean of its divisors is an integer number (14498640).

Almost surely, 2^64438390 is an apocalyptic number.

64438390 is a deficient number, since it is larger than the sum of its proper divisors (51550730).

64438390 is a wasteful number, since it uses less digits than its factorization.

64438390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6443846.

The product of its (nonzero) digits is 62208, while the sum is 37.

The square root of 64438390 is about 8027.3526146545. The cubic root of 64438390 is about 400.9112350504.

The spelling of 64438390 in words is "sixty-four million, four hundred thirty-eight thousand, three hundred ninety".