64821136 has 20 divisors (see below), whose sum is σ = 132979212. Its totient is φ = 30503936.

The previous prime is 64821079. The next prime is 64821137. The reversal of 64821136 is 63112846.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 60155536 + 4665600 = 7756^2 + 2160^2 .

It is a junction number, because it is equal to n+sod(n) for n = 64821098 and 64821107.

It is not an unprimeable number, because it can be changed into a prime (64821137) 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, 118885 + ... + 119428.

Almost surely, 2^64821136 is an apocalyptic number.

It is an amenable number.

64821136 is an abundant number, since it is smaller than the sum of its proper divisors (68158076).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64821136 is a wasteful number, since it uses less digits than its factorization.

64821136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238338 (or 238332 counting only the distinct ones).

The product of its digits is 6912, while the sum is 31.

The square root of 64821136 is about 8051.1574323199. The cubic root of 64821136 is about 401.7034354714.

The spelling of 64821136 in words is "sixty-four million, eight hundred twenty-one thousand, one hundred thirty-six".