64870321 has 4 divisors (see below), whose sum is σ = 66962944. Its totient is φ = 62777700.

The previous prime is 64870319. The next prime is 64870339. The reversal of 64870321 is 12307846.

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: 12307846 = 2 ⋅6153923.

It is a cyclic number.

It is not a de Polignac number, because 64870321 - 2¹ = 64870319 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 2092591 = 64870321 / (6 + 4 + 8 + 7 + 0 + 3 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64870391) 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, 1046265 + ... + 1046326.

It is an arithmetic number, because the mean of its divisors is an integer number (16740736).

Almost surely, 2^64870321 is an apocalyptic number.

It is an amenable number.

64870321 is a deficient number, since it is larger than the sum of its proper divisors (2092623).

64870321 is a wasteful number, since it uses less digits than its factorization.

64870321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2092622.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 64870321 is about 8054.2113828729. The cubic root of 64870321 is about 401.8050113335.

The spelling of 64870321 in words is "sixty-four million, eight hundred seventy thousand, three hundred twenty-one".