19319902978 has 4 divisors (see below), whose sum is σ = 28979854470. Its totient is φ = 9659951488.

The previous prime is 19319902969. The next prime is 19319903033. The reversal of 19319902978 is 87920991391.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14334554529 + 4985348449 = 119727^2 + 70607^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4829975743 + ... + 4829975746.

Almost surely, 2^19319902978 is an apocalyptic number.

19319902978 is a deficient number, since it is larger than the sum of its proper divisors (9659951492).

19319902978 is an equidigital number, since it uses as much as digits as its factorization.

19319902978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9659951491.

The product of its (nonzero) digits is 2204496, while the sum is 58.

The spelling of 19319902978 in words is "nineteen billion, three hundred nineteen million, nine hundred two thousand, nine hundred seventy-eight".