19550399 has 16 divisors (see below), whose sum is σ = 22208256. Its totient is φ = 17054400.

The previous prime is 19550387. The next prime is 19550407. The reversal of 19550399 is 99305591.

It is not a de Polignac number, because 19550399 - 2¹⁶ = 19484863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19550339) 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 in 15 ways as a sum of consecutive naturals, for example, 29894 + ... + 30540.

It is an arithmetic number, because the mean of its divisors is an integer number (1388016).

Almost surely, 2^19550399 is an apocalyptic number.

19550399 is a deficient number, since it is larger than the sum of its proper divisors (2657857).

19550399 is a wasteful number, since it uses less digits than its factorization.

19550399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766.

The product of its (nonzero) digits is 54675, while the sum is 41.

The square root of 19550399 is about 4421.5833137011. The cubic root of 19550399 is about 269.3923187491.

The spelling of 19550399 in words is "nineteen million, five hundred fifty thousand, three hundred ninety-nine".