64900009 has 2 divisors, whose sum is σ = 64900010. Its totient is φ = 64900008.

The previous prime is 64899979. The next prime is 64900021. The reversal of 64900009 is 90000946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63282025 + 1617984 = 7955^2 + 1272^2 .

It is a cyclic number.

It is not a de Polignac number, because 64900009 - 2¹⁵ = 64867241 is a prime.

It is a super-2 number, since 2×64900009² = 8424022336400162, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64900009.

It is not a weakly prime, because it can be changed into another prime (64900039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32450004 + 32450005.

It is an arithmetic number, because the mean of its divisors is an integer number (32450005).

Almost surely, 2^64900009 is an apocalyptic number.

It is an amenable number.

64900009 is a deficient number, since it is larger than the sum of its proper divisors (1).

64900009 is an equidigital number, since it uses as much as digits as its factorization.

64900009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 64900009 is about 8056.0541830353. The cubic root of 64900009 is about 401.8662975411.

It can be divided in two parts, 6 and 4900009, that added together give a triangular number (4900015 = T₃₁₃₀).

The spelling of 64900009 in words is "sixty-four million, nine hundred thousand, nine".