20919089 has 4 divisors (see below), whose sum is σ = 21364224. Its totient is φ = 20473956.

The previous prime is 20919049. The next prime is 20919109. The reversal of 20919089 is 98091902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20919089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20919049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222497 + ... + 222590.

It is an arithmetic number, because the mean of its divisors is an integer number (5341056).

Almost surely, 2^20919089 is an apocalyptic number.

It is an amenable number.

20919089 is a deficient number, since it is larger than the sum of its proper divisors (445135).

20919089 is an equidigital number, since it uses as much as digits as its factorization.

20919089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445134.

The product of its (nonzero) digits is 11664, while the sum is 38.

The square root of 20919089 is about 4573.7390612058. The cubic root of 20919089 is about 275.5376325263.

The spelling of 20919089 in words is "twenty million, nine hundred nineteen thousand, eighty-nine".