64838921 has 4 divisors (see below), whose sum is σ = 74101632. Its totient is φ = 55576212.

The previous prime is 64838861. The next prime is 64838927. The reversal of 64838921 is 12983846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12983846 = 2 ⋅6491923.

It is a cyclic number.

It is not a de Polignac number, because 64838921 - 2⁶ = 64838857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64838927) 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, 4631345 + ... + 4631358.

It is an arithmetic number, because the mean of its divisors is an integer number (18525408).

Almost surely, 2^64838921 is an apocalyptic number.

It is an amenable number.

64838921 is a deficient number, since it is larger than the sum of its proper divisors (9262711).

64838921 is an equidigital number, since it uses as much as digits as its factorization.

64838921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9262710.

The product of its digits is 82944, while the sum is 41.

The square root of 64838921 is about 8052.2618561495. The cubic root of 64838921 is about 401.7401706206.

The spelling of 64838921 in words is "sixty-four million, eight hundred thirty-eight thousand, nine hundred twenty-one".