20889729 has 48 divisors (see below), whose sum is σ = 36067200. Its totient is φ = 11642400.

The previous prime is 20889709. The next prime is 20889749. The reversal of 20889729 is 92798802.

It is an interprime number because it is at equal distance from previous prime (20889709) and next prime (20889749).

It is not a de Polignac number, because 20889729 - 2¹⁵ = 20856961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20889709) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 206779 + ... + 206879.

It is an arithmetic number, because the mean of its divisors is an integer number (751400).

Almost surely, 2^20889729 is an apocalyptic number.

It is an amenable number.

20889729 is a deficient number, since it is larger than the sum of its proper divisors (15177471).

20889729 is a wasteful number, since it uses less digits than its factorization.

20889729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 20889729 is about 4570.5283064434. The cubic root of 20889729 is about 275.4086662262.

The spelling of 20889729 in words is "twenty million, eight hundred eighty-nine thousand, seven hundred twenty-nine".