19923978 has 8 divisors (see below), whose sum is σ = 39847968. Its totient is φ = 6641324.

The previous prime is 19923977. The next prime is 19924013. The reversal of 19923978 is 87932991.

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

19923978 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (19923971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1660326 + ... + 1660337.

It is an arithmetic number, because the mean of its divisors is an integer number (4980996).

Almost surely, 2^19923978 is an apocalyptic number.

19923978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

19923978 is a wasteful number, since it uses less digits than its factorization.

19923978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3320668.

The product of its digits is 244944, while the sum is 48.

The square root of 19923978 is about 4463.6283447438. The cubic root of 19923978 is about 271.0973992115.

The spelling of 19923978 in words is "nineteen million, nine hundred twenty-three thousand, nine hundred seventy-eight".