64821911 has 16 divisors (see below), whose sum is σ = 81012480. Its totient is φ = 50388480.

The previous prime is 64821907. The next prime is 64821929. The reversal of 64821911 is 11912846.

It is a cyclic number.

It is not a de Polignac number, because 64821911 - 2² = 64821907 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 (64821971) 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, 43700 + ... + 45158.

It is an arithmetic number, because the mean of its divisors is an integer number (5063280).

Almost surely, 2^64821911 is an apocalyptic number.

64821911 is a deficient number, since it is larger than the sum of its proper divisors (16190569).

64821911 is a wasteful number, since it uses less digits than its factorization.

64821911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2054.

The product of its digits is 3456, while the sum is 32.

The square root of 64821911 is about 8051.2055619019. The cubic root of 64821911 is about 401.7050363840.

The spelling of 64821911 in words is "sixty-four million, eight hundred twenty-one thousand, nine hundred eleven".