21077930 has 16 divisors (see below), whose sum is σ = 38296800. Its totient is φ = 8351952.

The previous prime is 21077929. The next prime is 21077951. The reversal of 21077930 is 3977012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21077893 and 21077902.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8780 + ... + 10919.

It is an arithmetic number, because the mean of its divisors is an integer number (2393550).

Almost surely, 2^21077930 is an apocalyptic number.

21077930 is a deficient number, since it is larger than the sum of its proper divisors (17218870).

21077930 is a wasteful number, since it uses less digits than its factorization.

21077930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19813.

The product of its (nonzero) digits is 2646, while the sum is 29.

The square root of 21077930 is about 4591.0706812246. The cubic root of 21077930 is about 276.2332708965.

The spelling of 21077930 in words is "twenty-one million, seventy-seven thousand, nine hundred thirty".