20899469 has 2 divisors, whose sum is σ = 20899470. Its totient is φ = 20899468.

The previous prime is 20899453. The next prime is 20899471. The reversal of 20899469 is 96499802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19909444 + 990025 = 4462^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 20899469 - 2⁴ = 20899453 is a prime.

It is a super-2 number, since 2×20899469² = 873575608963922, which contains 22 as substring.

Together with 20899471, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20899499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10449734 + 10449735.

It is an arithmetic number, because the mean of its divisors is an integer number (10449735).

Almost surely, 2^20899469 is an apocalyptic number.

It is an amenable number.

20899469 is a deficient number, since it is larger than the sum of its proper divisors (1).

20899469 is an equidigital number, since it uses as much as digits as its factorization.

20899469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 47.

The square root of 20899469 is about 4571.5937046067. The cubic root of 20899469 is about 275.4514633924.

The spelling of 20899469 in words is "twenty million, eight hundred ninety-nine thousand, four hundred sixty-nine".