64533621 has 4 divisors (see below), whose sum is σ = 86044832. Its totient is φ = 43022412.

The previous prime is 64533619. The next prime is 64533641. The reversal of 64533621 is 12633546.

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.

It is not a de Polignac number, because 64533621 - 2¹ = 64533619 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64533611) 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, 10755601 + ... + 10755606.

It is an arithmetic number, because the mean of its divisors is an integer number (21511208).

Almost surely, 2^64533621 is an apocalyptic number.

It is an amenable number.

64533621 is a deficient number, since it is larger than the sum of its proper divisors (21511211).

64533621 is a wasteful number, since it uses less digits than its factorization.

64533621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21511210.

The product of its digits is 12960, while the sum is 30.

The square root of 64533621 is about 8033.2820814409. The cubic root of 64533621 is about 401.1086348996.

The spelling of 64533621 in words is "sixty-four million, five hundred thirty-three thousand, six hundred twenty-one".