19749636450 has 288 divisors, whose sum is σ = 58350015360. Its totient is φ = 4771353600.

The previous prime is 19749636443. The next prime is 19749636509. The reversal of 19749636450 is 5463694791.

19749636450 is a `hidden beast` number, since 1 + 9 + 74 + 96 + 36 + 450 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 18578619 + ... + 18579681.

It is an arithmetic number, because the mean of its divisors is an integer number (202604220).

Almost surely, 2^19749636450 is an apocalyptic number.

19749636450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19749636450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29175007680).

19749636450 is an abundant number, since it is smaller than the sum of its proper divisors (38600378910).

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

19749636450 is a wasteful number, since it uses less digits than its factorization.

19749636450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194 (or 1186 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 19749636450 in words is "nineteen billion, seven hundred forty-nine million, six hundred thirty-six thousand, four hundred fifty".