21077009 has 8 divisors (see below), whose sum is σ = 22028160. Its totient is φ = 20146896.

The previous prime is 21076981. The next prime is 21077011. The reversal of 21077009 is 90077012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21077009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21070009) 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, 3194 + ... + 7235.

It is an arithmetic number, because the mean of its divisors is an integer number (2753520).

Almost surely, 2^21077009 is an apocalyptic number.

It is an amenable number.

21077009 is a deficient number, since it is larger than the sum of its proper divisors (951151).

21077009 is a wasteful number, since it uses less digits than its factorization.

21077009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10519.

The product of its (nonzero) digits is 882, while the sum is 26.

The square root of 21077009 is about 4590.9703767286. The cubic root of 21077009 is about 276.2292475009.

The spelling of 21077009 in words is "twenty-one million, seventy-seven thousand, nine".