19809694 has 4 divisors (see below), whose sum is σ = 29714544. Its totient is φ = 9904846.

The previous prime is 19809679. The next prime is 19809721. The reversal of 19809694 is 49690891.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4952422 + ... + 4952425.

It is an arithmetic number, because the mean of its divisors is an integer number (7428636).

Almost surely, 2^19809694 is an apocalyptic number.

19809694 is a deficient number, since it is larger than the sum of its proper divisors (9904850).

19809694 is an equidigital number, since it uses as much as digits as its factorization.

19809694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9904849.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 19809694 is about 4450.8082412074. The cubic root of 19809694 is about 270.5780664680.

It can be divided in two parts, 19809 and 694, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 19809694 in words is "nineteen million, eight hundred nine thousand, six hundred ninety-four".