19979916 has 48 divisors (see below), whose sum is σ = 53077248. Its totient is φ = 5790400.

The previous prime is 19979909. The next prime is 19979923. The reversal of 19979916 is 61997991.

It is an interprime number because it is at equal distance from previous prime (19979909) and next prime (19979923).

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, 255 + ... + 6326.

It is an arithmetic number, because the mean of its divisors is an integer number (1105776).

Almost surely, 2^19979916 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 19979916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26538624).

19979916 is an abundant number, since it is smaller than the sum of its proper divisors (33097332).

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

19979916 is a wasteful number, since it uses less digits than its factorization.

19979916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6622 (or 6620 counting only the distinct ones).

The product of its digits is 275562, while the sum is 51.

The square root of 19979916 is about 4469.8899315308. The cubic root of 19979916 is about 271.3508706228.

The spelling of 19979916 in words is "nineteen million, nine hundred seventy-nine thousand, nine hundred sixteen".