64197819 has 16 divisors (see below), whose sum is σ = 108695040. Its totient is φ = 36684360.

The previous prime is 64197811. The next prime is 64197863. The reversal of 64197819 is 91879146.

It is a happy number.

It is not a de Polignac number, because 64197819 - 2³ = 64197811 is a prime.

It is a super-2 number, since 2×64197819² = 8242719928713522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (64197811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169647 + ... + 170024.

It is an arithmetic number, because the mean of its divisors is an integer number (6793440).

Almost surely, 2^64197819 is an apocalyptic number.

64197819 is a deficient number, since it is larger than the sum of its proper divisors (44497221).

64197819 is a wasteful number, since it uses less digits than its factorization.

64197819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339687 (or 339681 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 64197819 is about 8012.3541484385. The cubic root of 64197819 is about 400.4116990311.

The spelling of 64197819 in words is "sixty-four million, one hundred ninety-seven thousand, eight hundred nineteen".