19894936656 has 160 divisors (see below), whose sum is σ = 59594185728. Its totient is φ = 5601715200.

The previous prime is 19894936643. The next prime is 19894936669. The reversal of 19894936656 is 65663949891.

It is an interprime number because it is at equal distance from previous prime (19894936643) and next prime (19894936669).

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 in 31 ways as a sum of consecutive naturals, for example, 16760095 + ... + 16761281.

Almost surely, 2^19894936656 is an apocalyptic number.

19894936656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19894936656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29797092864).

19894936656 is an abundant number, since it is smaller than the sum of its proper divisors (39699249072).

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

19894936656 is a wasteful number, since it uses less digits than its factorization.

19894936656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1889 (or 1883 counting only the distinct ones).

The product of its digits is 75582720, while the sum is 66.

The spelling of 19894936656 in words is "nineteen billion, eight hundred ninety-four million, nine hundred thirty-six thousand, six hundred fifty-six".