19990691746 has 16 divisors (see below), whose sum is σ = 30544332120. Its totient is φ = 9810887680.

The previous prime is 19990691729. The next prime is 19990691759. The reversal of 19990691746 is 64719609991.

It can be written as a sum of positive squares in 4 ways, for example, as 16148055625 + 3842636121 = 127075^2 + 61989^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 385495 + ... + 434266.

Almost surely, 2^19990691746 is an apocalyptic number.

19990691746 is a deficient number, since it is larger than the sum of its proper divisors (10553640374).

19990691746 is a wasteful number, since it uses less digits than its factorization.

19990691746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819989.

The product of its (nonzero) digits is 6613488, while the sum is 61.

The spelling of 19990691746 in words is "nineteen billion, nine hundred ninety million, six hundred ninety-one thousand, seven hundred forty-six".