19871628 has 48 divisors (see below), whose sum is σ = 53324544. Its totient is φ = 5641920.

The previous prime is 19871603. The next prime is 19871629. The reversal of 19871628 is 82617891.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 19871628.

It is not an unprimeable number, because it can be changed into a prime (19871629) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14551 + ... + 15857.

It is an arithmetic number, because the mean of its divisors is an integer number (1110928).

Almost surely, 2^19871628 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19871628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26662272).

19871628 is an abundant number, since it is smaller than the sum of its proper divisors (33452916).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19871628 is a wasteful number, since it uses less digits than its factorization.

19871628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1502 (or 1500 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 19871628 is about 4457.7604242489. The cubic root of 19871628 is about 270.8597559599.

The spelling of 19871628 in words is "nineteen million, eight hundred seventy-one thousand, six hundred twenty-eight".