64403621 has 4 divisors (see below), whose sum is σ = 65005632. Its totient is φ = 63801612.

The previous prime is 64403567. The next prime is 64403623. The reversal of 64403621 is 12630446.

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: 12630446 = 2 ⋅6315223.

It is a cyclic number.

It is not a de Polignac number, because 64403621 - 2¹⁴ = 64387237 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64403623) 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, 300845 + ... + 301058.

It is an arithmetic number, because the mean of its divisors is an integer number (16251408).

Almost surely, 2^64403621 is an apocalyptic number.

It is an amenable number.

64403621 is a deficient number, since it is larger than the sum of its proper divisors (602011).

64403621 is a wasteful number, since it uses less digits than its factorization.

64403621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602010.

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 64403621 is about 8025.1866644957. The cubic root of 64403621 is about 400.8391155651.

The spelling of 64403621 in words is "sixty-four million, four hundred three thousand, six hundred twenty-one".