64820393 has 12 divisors (see below), whose sum is σ = 72418608. Its totient is φ = 57539160.

The previous prime is 64820387. The next prime is 64820407. The reversal of 64820393 is 39302846.

It is a happy number.

It is not a de Polignac number, because 64820393 - 2⁸ = 64820137 is a prime.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64820333) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18746 + ... + 21932.

It is an arithmetic number, because the mean of its divisors is an integer number (6034884).

Almost surely, 2^64820393 is an apocalyptic number.

64820393 is the 4304-th centered heptagonal number.

It is an amenable number.

64820393 is a deficient number, since it is larger than the sum of its proper divisors (7598215).

64820393 is a wasteful number, since it uses less digits than its factorization.

64820393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3284 (or 3241 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The square root of 64820393 is about 8051.1112897537. Note that the first 3 decimals coincide. The cubic root of 64820393 is about 401.7019006490.

The spelling of 64820393 in words is "sixty-four million, eight hundred twenty thousand, three hundred ninety-three".