19812881634 has 192 divisors, whose sum is σ = 51090554880. Its totient is φ = 5009921280.

The previous prime is 19812881629. The next prime is 19812881639. The reversal of 19812881634 is 43618821891.

It is an interprime number because it is at equal distance from previous prime (19812881629) and next prime (19812881639).

It is a super-3 number, since 3×19812881634³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (19812881639) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 27944472 + ... + 27945180.

It is an arithmetic number, because the mean of its divisors is an integer number (266096640).

Almost surely, 2^19812881634 is an apocalyptic number.

19812881634 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19812881634, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25545277440).

19812881634 is an abundant number, since it is smaller than the sum of its proper divisors (31277673246).

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

19812881634 is a wasteful number, since it uses less digits than its factorization.

19812881634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905 (or 892 counting only the distinct ones).

The product of its digits is 663552, while the sum is 51.

The spelling of 19812881634 in words is "nineteen billion, eight hundred twelve million, eight hundred eighty-one thousand, six hundred thirty-four".