20369551 has 2 divisors, whose sum is σ = 20369552. Its totient is φ = 20369550.

The previous prime is 20369549. The next prime is 20369581. The reversal of 20369551 is 15596302.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20369551 - 2¹ = 20369549 is a prime.

Together with 20369549, it forms a pair of twin primes.

It is equal to p_1292557 and since 20369551 and 1292557 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20369521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10184775 + 10184776.

It is an arithmetic number, because the mean of its divisors is an integer number (10184776).

Almost surely, 2^20369551 is an apocalyptic number.

20369551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20369551 is an equidigital number, since it uses as much as digits as its factorization.

20369551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 31.

The square root of 20369551 is about 4513.2638965609. The cubic root of 20369551 is about 273.1034283644.

The spelling of 20369551 in words is "twenty million, three hundred sixty-nine thousand, five hundred fifty-one".