64402009 has 4 divisors (see below), whose sum is σ = 73602304. Its totient is φ = 55201716.

The previous prime is 64402007. The next prime is 64402033. The reversal of 64402009 is 90020446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90020446 = 2 ⋅45010223.

It is a cyclic number.

It is not a de Polignac number, because 64402009 - 2¹ = 64402007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64402007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4600137 + ... + 4600150.

It is an arithmetic number, because the mean of its divisors is an integer number (18400576).

Almost surely, 2^64402009 is an apocalyptic number.

It is an amenable number.

64402009 is a deficient number, since it is larger than the sum of its proper divisors (9200295).

64402009 is an equidigital number, since it uses as much as digits as its factorization.

64402009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9200294.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 64402009 is about 8025.0862300663. The cubic root of 64402009 is about 400.8357712498.

The spelling of 64402009 in words is "sixty-four million, four hundred two thousand, nine".