64727621 has 4 divisors (see below), whose sum is σ = 73974432. Its totient is φ = 55480812.

The previous prime is 64727609. The next prime is 64727651. The reversal of 64727621 is 12672746.

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: 12672746 = 2 ⋅6336373.

It is a cyclic number.

It is not a de Polignac number, because 64727621 - 2⁶ = 64727557 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64727651) 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, 4623395 + ... + 4623408.

It is an arithmetic number, because the mean of its divisors is an integer number (18493608).

Almost surely, 2^64727621 is an apocalyptic number.

It is an amenable number.

64727621 is a deficient number, since it is larger than the sum of its proper divisors (9246811).

64727621 is an equidigital number, since it uses as much as digits as its factorization.

64727621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9246810.

The product of its digits is 28224, while the sum is 35.

The square root of 64727621 is about 8045.3477861432. The cubic root of 64727621 is about 401.5101683867.

The spelling of 64727621 in words is "sixty-four million, seven hundred twenty-seven thousand, six hundred twenty-one".