19987387 has 8 divisors (see below), whose sum is σ = 23023616. Its totient is φ = 16996392.

The previous prime is 19987379. The next prime is 19987399. The reversal of 19987387 is 78378991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19987387 - 2³ = 19987379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19987367) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10353 + ... + 12130.

It is an arithmetic number, because the mean of its divisors is an integer number (2877952).

Almost surely, 2^19987387 is an apocalyptic number.

19987387 is a deficient number, since it is larger than the sum of its proper divisors (3036229).

19987387 is a wasteful number, since it uses less digits than its factorization.

19987387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22617.

The product of its digits is 762048, while the sum is 52.

The square root of 19987387 is about 4470.7255563275. The cubic root of 19987387 is about 271.3846880777.

The spelling of 19987387 in words is "nineteen million, nine hundred eighty-seven thousand, three hundred eighty-seven".