64809189963 has 64 divisors (see below), whose sum is σ = 111479280640. Its totient is φ = 36447667200.

The previous prime is 64809189959. The next prime is 64809189983. The reversal of 64809189963 is 36998190846.

It is a happy number.

64809189963 is a `hidden beast` number, since 6 + 480 + 9 + 1 + 8 + 99 + 63 = 666.

It is not a de Polignac number, because 64809189963 - 2² = 64809189959 is a prime.

It is a super-2 number, since 2×64809189963² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a self number, because there is not a number n which added to its sum of digits gives 64809189963.

It is not an unprimeable number, because it can be changed into a prime (64809189953) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3308508 + ... + 3328038.

It is an arithmetic number, because the mean of its divisors is an integer number (1741863760).

Almost surely, 2^64809189963 is an apocalyptic number.

64809189963 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

64809189963 is a deficient number, since it is larger than the sum of its proper divisors (46670090677).

64809189963 is a wasteful number, since it uses less digits than its factorization.

64809189963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19825 (or 19819 counting only the distinct ones).

The product of its (nonzero) digits is 20155392, while the sum is 63.

The spelling of 64809189963 in words is "sixty-four billion, eight hundred nine million, one hundred eighty-nine thousand, nine hundred sixty-three".