64378621 has 2 divisors, whose sum is σ = 64378622. Its totient is φ = 64378620.

The previous prime is 64378543. The next prime is 64378649. The reversal of 64378621 is 12687346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64176121 + 202500 = 8011^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 64378621 - 2⁷ = 64378493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64372621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32189310 + 32189311.

It is an arithmetic number, because the mean of its divisors is an integer number (32189311).

Almost surely, 2^64378621 is an apocalyptic number.

It is an amenable number.

64378621 is a deficient number, since it is larger than the sum of its proper divisors (1).

64378621 is an equidigital number, since it uses as much as digits as its factorization.

64378621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 37.

The square root of 64378621 is about 8023.6289171422. The cubic root of 64378621 is about 400.7872433533.

The spelling of 64378621 in words is "sixty-four million, three hundred seventy-eight thousand, six hundred twenty-one".