19988400 has 60 divisors (see below), whose sum is σ = 64033352. Its totient is φ = 5329920.

The previous prime is 19988383. The next prime is 19988411. The reversal of 19988400 is 488991.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×19988400² = 799072269120000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7129 + ... + 9528.

Almost surely, 2^19988400 is an apocalyptic number.

19988400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19988400 is an abundant number, since it is smaller than the sum of its proper divisors (44044952).

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

19988400 is a wasteful number, since it uses less digits than its factorization.

19988400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16678 (or 16667 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 19988400 is about 4470.8388474648. The cubic root of 19988400 is about 271.3892727697.

The spelling of 19988400 in words is "nineteen million, nine hundred eighty-eight thousand, four hundred".