219990509 has 4 divisors (see below), whose sum is σ = 220030560. Its totient is φ = 219950460.

The previous prime is 219990497. The next prime is 219990517. The reversal of 219990509 is 905099912.

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.

It is a cyclic number.

It is not a de Polignac number, because 219990509 - 2¹² = 219986413 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 219990509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (219990599) 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, 10169 + ... + 23310.

It is an arithmetic number, because the mean of its divisors is an integer number (55007640).

Almost surely, 2^219990509 is an apocalyptic number.

It is an amenable number.

219990509 is a deficient number, since it is larger than the sum of its proper divisors (40051).

219990509 is an equidigital number, since it uses as much as digits as its factorization.

219990509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40050.

The product of its (nonzero) digits is 65610, while the sum is 44.

The square root of 219990509 is about 14832.0770291959. The cubic root of 219990509 is about 603.6723924382.

The spelling of 219990509 in words is "two hundred nineteen million, nine hundred ninety thousand, five hundred nine".