219987994 has 4 divisors (see below), whose sum is σ = 329981994. Its totient is φ = 109993996.

The previous prime is 219987991. The next prime is 219988009. The reversal of 219987994 is 499789912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 216472369 + 3515625 = 14713^2 + 1875^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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 as a sum of consecutive naturals, namely, 54996997 + ... + 54997000.

Almost surely, 2^219987994 is an apocalyptic number.

219987994 is a deficient number, since it is larger than the sum of its proper divisors (109994000).

219987994 is a wasteful number, since it uses less digits than its factorization.

219987994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109993999.

The product of its digits is 2939328, while the sum is 58.

The square root of 219987994 is about 14831.9922464920. The cubic root of 219987994 is about 603.6700919725.

It can be divided in two parts, 21998 and 7994, that added together give a palindrome (29992).

The spelling of 219987994 in words is "two hundred nineteen million, nine hundred eighty-seven thousand, nine hundred ninety-four".