64391081 has 16 divisors (see below), whose sum is σ = 68057088. Its totient is φ = 60858000.

The previous prime is 64391077. The next prime is 64391111. The reversal of 64391081 is 18019346.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 64391081 - 2² = 64391077 is a prime.

It is a super-2 number, since 2×64391081² = 8292422624697122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64391071) 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, 305066 + ... + 305276.

It is an arithmetic number, because the mean of its divisors is an integer number (4253568).

Almost surely, 2^64391081 is an apocalyptic number.

It is an amenable number.

64391081 is a deficient number, since it is larger than the sum of its proper divisors (3666007).

64391081 is a wasteful number, since it uses less digits than its factorization.

64391081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 64391081 is about 8024.4053362227. The cubic root of 64391081 is about 400.8130981419.

The spelling of 64391081 in words is "sixty-four million, three hundred ninety-one thousand, eighty-one".