19951680 has 112 divisors (see below), whose sum is σ = 72420480. Its totient is φ = 4558848.

The previous prime is 19951661. The next prime is 19951709. The reversal of 19951680 is 8615991.

It is a tau number, because it is divible by the number of its divisors (112).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5236 + ... + 8204.

Almost surely, 2^19951680 is an apocalyptic number.

19951680 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 19951680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36210240).

19951680 is an abundant number, since it is smaller than the sum of its proper divisors (52468800).

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

19951680 is a wasteful number, since it uses less digits than its factorization.

19951680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2996 (or 2986 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 19951680 is about 4466.7303478048. The cubic root of 19951680 is about 271.2229842773. Note that the first 3 decimals are identical.

The spelling of 19951680 in words is "nineteen million, nine hundred fifty-one thousand, six hundred eighty".