19697978 has 8 divisors (see below), whose sum is σ = 29665440. Its totient is φ = 9809500.

The previous prime is 19697969. The next prime is 19698031. The reversal of 19697978 is 87979691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19118 + ... + 20121.

It is an arithmetic number, because the mean of its divisors is an integer number (3708180).

Almost surely, 2^19697978 is an apocalyptic number.

19697978 is a deficient number, since it is larger than the sum of its proper divisors (9967462).

19697978 is a wasteful number, since it uses less digits than its factorization.

19697978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39492.

The product of its digits is 1714608, while the sum is 56.

The square root of 19697978 is about 4438.2404171023. The cubic root of 19697978 is about 270.0684691467.

The spelling of 19697978 in words is "nineteen million, six hundred ninety-seven thousand, nine hundred seventy-eight".