19954987 has 16 divisors (see below), whose sum is σ = 22790880. Its totient is φ = 17337600.

The previous prime is 19954981. The next prime is 19955029. The reversal of 19954987 is 78945991.

It is a cyclic number.

It is not a de Polignac number, because 19954987 - 2¹¹ = 19952939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19954981) 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, 14812 + ... + 16102.

It is an arithmetic number, because the mean of its divisors is an integer number (1424430).

Almost surely, 2^19954987 is an apocalyptic number.

19954987 is a deficient number, since it is larger than the sum of its proper divisors (2835893).

19954987 is a wasteful number, since it uses less digits than its factorization.

19954987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1374.

The product of its digits is 816480, while the sum is 52.

The square root of 19954987 is about 4467.1005137561. The cubic root of 19954987 is about 271.2379685603.

The spelling of 19954987 in words is "nineteen million, nine hundred fifty-four thousand, nine hundred eighty-seven".