19918019694 has 16 divisors (see below), whose sum is σ = 41932673280. Its totient is φ = 6289900920.

The previous prime is 19918019677. The next prime is 19918019707. The reversal of 19918019694 is 49691081991.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87359622 + ... + 87359849.

It is an arithmetic number, because the mean of its divisors is an integer number (2620792080).

Almost surely, 2^19918019694 is an apocalyptic number.

19918019694 is an abundant number, since it is smaller than the sum of its proper divisors (22014653586).

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

19918019694 is a wasteful number, since it uses less digits than its factorization.

19918019694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174719495.

The product of its (nonzero) digits is 1259712, while the sum is 57.

The spelling of 19918019694 in words is "nineteen billion, nine hundred eighteen million, nineteen thousand, six hundred ninety-four".