64305809 has 2 divisors, whose sum is σ = 64305810. Its totient is φ = 64305808.

The previous prime is 64305803. The next prime is 64305821. The reversal of 64305809 is 90850346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64000000 + 305809 = 8000^2 + 553^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64305809 is a prime.

It is a super-2 number, since 2×64305809² = 8270474142288962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64305803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32152904 + 32152905.

It is an arithmetic number, because the mean of its divisors is an integer number (32152905).

Almost surely, 2^64305809 is an apocalyptic number.

It is an amenable number.

64305809 is a deficient number, since it is larger than the sum of its proper divisors (1).

64305809 is an equidigital number, since it uses as much as digits as its factorization.

64305809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 64305809 is about 8019.0902850635. The cubic root of 64305809 is about 400.6360900209.

It can be divided in two parts, 64 and 305809, that multiplied together give a square (19571776 = 4424²).

The spelling of 64305809 in words is "sixty-four million, three hundred five thousand, eight hundred nine".