19871428 has 6 divisors (see below), whose sum is σ = 34775006. Its totient is φ = 9935712.

The previous prime is 19871417. The next prime is 19871437. The reversal of 19871428 is 82417891.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18507204 + 1364224 = 4302^2 + 1168^2 .

It is an unprimeable number.

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, 2483925 + ... + 2483932.

Almost surely, 2^19871428 is an apocalyptic number.

It is an amenable number.

19871428 is a deficient number, since it is larger than the sum of its proper divisors (14903578).

19871428 is a wasteful number, since it uses less digits than its factorization.

19871428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4967861 (or 4967859 counting only the distinct ones).

The product of its digits is 32256, while the sum is 40.

The square root of 19871428 is about 4457.7379914033. The cubic root of 19871428 is about 270.8588472584.

The spelling of 19871428 in words is "nineteen million, eight hundred seventy-one thousand, four hundred twenty-eight".