64405819 has 8 divisors (see below), whose sum is σ = 67803552. Its totient is φ = 61057920.

The previous prime is 64405771. The next prime is 64405853. The reversal of 64405819 is 91850446.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 64405819 - 2²³ = 56017211 is a prime.

It is a super-2 number, since 2×64405819² = 8296219042121522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64405889) 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, 9792 + ... + 14989.

It is an arithmetic number, because the mean of its divisors is an integer number (8475444).

Almost surely, 2^64405819 is an apocalyptic number.

64405819 is a deficient number, since it is larger than the sum of its proper divisors (3397733).

64405819 is a wasteful number, since it uses less digits than its factorization.

64405819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24917.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 64405819 is about 8025.3236071825. The cubic root of 64405819 is about 400.8436755279.

The spelling of 64405819 in words is "sixty-four million, four hundred five thousand, eight hundred nineteen".