64836821 has 8 divisors (see below), whose sum is σ = 74156544. Its totient is φ = 55531440.

The previous prime is 64836817. The next prime is 64836823. The reversal of 64836821 is 12863846.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64836821 - 2² = 64836817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64836823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9116 + ... + 14586.

It is an arithmetic number, because the mean of its divisors is an integer number (9269568).

Almost surely, 2^64836821 is an apocalyptic number.

It is an amenable number.

64836821 is a deficient number, since it is larger than the sum of its proper divisors (9319723).

64836821 is a wasteful number, since it uses less digits than its factorization.

64836821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7171.

The product of its digits is 55296, while the sum is 38.

The square root of 64836821 is about 8052.1314569498. The cubic root of 64836821 is about 401.7358333930.

The spelling of 64836821 in words is "sixty-four million, eight hundred thirty-six thousand, eight hundred twenty-one".