19961389 has 12 divisors (see below), whose sum is σ = 23457504. Its totient is φ = 16639344.

The previous prime is 19961371. The next prime is 19961393. The reversal of 19961389 is 98316991.

It is not a de Polignac number, because 19961389 - 2¹¹ = 19959341 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19961329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8542 + ... + 10624.

It is an arithmetic number, because the mean of its divisors is an integer number (1954792).

Almost surely, 2^19961389 is an apocalyptic number.

It is an amenable number.

19961389 is a deficient number, since it is larger than the sum of its proper divisors (3496115).

19961389 is an equidigital number, since it uses as much as digits as its factorization.

19961389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2164 (or 2127 counting only the distinct ones).

The product of its digits is 104976, while the sum is 46.

The square root of 19961389 is about 4467.8170284827. The cubic root of 19961389 is about 271.2669718334.

The spelling of 19961389 in words is "nineteen million, nine hundred sixty-one thousand, three hundred eighty-nine".