19902438494 has 8 divisors (see below), whose sum is σ = 30359652120. Its totient is φ = 9782554456.

The previous prime is 19902438419. The next prime is 19902438527. The reversal of 19902438494 is 49483420991.

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

It is a super-2 number, since 2×19902438494² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84332249 + ... + 84332484.

It is an arithmetic number, because the mean of its divisors is an integer number (3794956515).

Almost surely, 2^19902438494 is an apocalyptic number.

19902438494 is a deficient number, since it is larger than the sum of its proper divisors (10457213626).

19902438494 is a wasteful number, since it uses less digits than its factorization.

19902438494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168664794.

The product of its (nonzero) digits is 2239488, while the sum is 53.

The spelling of 19902438494 in words is "nineteen billion, nine hundred two million, four hundred thirty-eight thousand, four hundred ninety-four".