64815943 has 4 divisors (see below), whose sum is σ = 65445328. Its totient is φ = 64186560.

The previous prime is 64815929. The next prime is 64815983. The reversal of 64815943 is 34951846.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64815943 - 2⁵ = 64815911 is a prime.

It is a super-2 number, since 2×64815943² = 8402212933958498, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64815896 and 64815905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64815983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 314538 + ... + 314743.

It is an arithmetic number, because the mean of its divisors is an integer number (16361332).

Almost surely, 2^64815943 is an apocalyptic number.

64815943 is a deficient number, since it is larger than the sum of its proper divisors (629385).

64815943 is a wasteful number, since it uses less digits than its factorization.

64815943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629384.

The product of its digits is 103680, while the sum is 40.

The square root of 64815943 is about 8050.8349256459. The cubic root of 64815943 is about 401.6927079948.

The spelling of 64815943 in words is "sixty-four million, eight hundred fifteen thousand, nine hundred forty-three".