21799768 has 32 divisors (see below), whose sum is σ = 42910560. Its totient is φ = 10362880.

The previous prime is 21799759. The next prime is 21799777. The reversal of 21799768 is 86799712.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21799759) and next prime (21799777).

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 47058 + ... + 47518.

It is an arithmetic number, because the mean of its divisors is an integer number (1340955).

Almost surely, 2^21799768 is an apocalyptic number.

It is an amenable number.

21799768 is a deficient number, since it is larger than the sum of its proper divisors (21110792).

21799768 is a wasteful number, since it uses less digits than its factorization.

21799768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747 (or 743 counting only the distinct ones).

The product of its digits is 381024, while the sum is 49.

The square root of 21799768 is about 4669.0221674351. The cubic root of 21799768 is about 279.3512531469.

The spelling of 21799768 in words is "twenty-one million, seven hundred ninety-nine thousand, seven hundred sixty-eight".