21788996 has 6 divisors (see below), whose sum is σ = 38130750. Its totient is φ = 10894496.

The previous prime is 21788983. The next prime is 21789007. The reversal of 21788996 is 69988712.

It can be written as a sum of positive squares in only one way, i.e., 21752896 + 36100 = 4664^2 + 190^2 .

It is an unprimeable number.

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, 2723621 + ... + 2723628.

It is an arithmetic number, because the mean of its divisors is an integer number (6355125).

Almost surely, 2^21788996 is an apocalyptic number.

It is an amenable number.

21788996 is a deficient number, since it is larger than the sum of its proper divisors (16341754).

21788996 is a wasteful number, since it uses less digits than its factorization.

21788996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5447253 (or 5447251 counting only the distinct ones).

The product of its digits is 435456, while the sum is 50.

The square root of 21788996 is about 4667.8684642993. The cubic root of 21788996 is about 279.3052332768.

The spelling of 21788996 in words is "twenty-one million, seven hundred eighty-eight thousand, nine hundred ninety-six".