19978680 has 64 divisors (see below), whose sum is σ = 62013600. Its totient is φ = 5143040.

The previous prime is 19978667. The next prime is 19978733. The reversal of 19978680 is 8687991.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 610 + ... + 6350.

Almost surely, 2^19978680 is an apocalyptic number.

19978680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19978680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31006800).

19978680 is an abundant number, since it is smaller than the sum of its proper divisors (42034920).

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

19978680 is a wasteful number, since it uses less digits than its factorization.

19978680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5784 (or 5780 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 19978680 is about 4469.7516709544. The cubic root of 19978680 is about 271.3452750605.

The spelling of 19978680 in words is "nineteen million, nine hundred seventy-eight thousand, six hundred eighty".