21779006 has 16 divisors (see below), whose sum is σ = 34791120. Its totient is φ = 10189440.

The previous prime is 21779003. The next prime is 21779011. The reversal of 21779006 is 60097712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21779003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4385 + ... + 7923.

It is an arithmetic number, because the mean of its divisors is an integer number (2174445).

Almost surely, 2^21779006 is an apocalyptic number.

21779006 is a deficient number, since it is larger than the sum of its proper divisors (13012114).

21779006 is a wasteful number, since it uses less digits than its factorization.

21779006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3739.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 21779006 is about 4666.7982600494. The cubic root of 21779006 is about 279.2625406897.

The spelling of 21779006 in words is "twenty-one million, seven hundred seventy-nine thousand, six".