64940221 has 16 divisors (see below), whose sum is σ = 70357248. Its totient is φ = 59718400.

The previous prime is 64940209. The next prime is 64940243. The reversal of 64940221 is 12204946.

It is a cyclic number.

It is not a de Polignac number, because 64940221 - 2⁵ = 64940189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64940221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64940021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 208656 + ... + 208966.

It is an arithmetic number, because the mean of its divisors is an integer number (4397328).

Almost surely, 2^64940221 is an apocalyptic number.

It is an amenable number.

64940221 is a deficient number, since it is larger than the sum of its proper divisors (5417027).

64940221 is a wasteful number, since it uses less digits than its factorization.

64940221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 64940221 is about 8058.5495593190. The cubic root of 64940221 is about 401.9492790970.

The spelling of 64940221 in words is "sixty-four million, nine hundred forty thousand, two hundred twenty-one".