20989727 has 4 divisors (see below), whose sum is σ = 22897896. Its totient is φ = 19081560.

The previous prime is 20989711. The next prime is 20989739. The reversal of 20989727 is 72798902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20989727 - 2⁴ = 20989711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989757) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 954068 + ... + 954089.

It is an arithmetic number, because the mean of its divisors is an integer number (5724474).

Almost surely, 2^20989727 is an apocalyptic number.

20989727 is a deficient number, since it is larger than the sum of its proper divisors (1908169).

20989727 is a wasteful number, since it uses less digits than its factorization.

20989727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1908168.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 20989727 is about 4581.4546816486. The cubic root of 20989727 is about 275.8474223192.

The spelling of 20989727 in words is "twenty million, nine hundred eighty-nine thousand, seven hundred twenty-seven".