219987993 has 4 divisors (see below), whose sum is σ = 293317328. Its totient is φ = 146658660.

The previous prime is 219987991. The next prime is 219988009. The reversal of 219987993 is 399789912.

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 not a de Polignac number, because 219987993 - 2¹ = 219987991 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (219987991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36664663 + ... + 36664668.

It is an arithmetic number, because the mean of its divisors is an integer number (73329332).

Almost surely, 2^219987993 is an apocalyptic number.

It is an amenable number.

219987993 is a deficient number, since it is larger than the sum of its proper divisors (73329335).

219987993 is an equidigital number, since it uses as much as digits as its factorization.

219987993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73329334.

The product of its digits is 2204496, while the sum is 57.

The square root of 219987993 is about 14831.9922127811. The cubic root of 219987993 is about 603.6700910578.

The spelling of 219987993 in words is "two hundred nineteen million, nine hundred eighty-seven thousand, nine hundred ninety-three".