21779044 has 24 divisors (see below), whose sum is σ = 43666560. Its totient is φ = 9310656.

The previous prime is 21779033. The next prime is 21779063. The reversal of 21779044 is 44097712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15249 + ... + 16615.

It is an arithmetic number, because the mean of its divisors is an integer number (1819440).

Almost surely, 2^21779044 is an apocalyptic number.

It is an amenable number.

21779044 is an abundant number, since it is smaller than the sum of its proper divisors (21887516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21779044 is a wasteful number, since it uses less digits than its factorization.

21779044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1947 (or 1945 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 21779044 is about 4666.8023313614. The cubic root of 21779044 is about 279.2627031087.

The spelling of 21779044 in words is "twenty-one million, seven hundred seventy-nine thousand, forty-four".