1981406336 has 192 divisors, whose sum is σ = 5209344000. Its totient is φ = 742017024.

The previous prime is 1981406333. The next prime is 1981406341. The reversal of 1981406336 is 6336041891.

It is a super-3 number, since 3×1981406336³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1981406293 and 1981406302.

It is not an unprimeable number, because it can be changed into a prime (1981406333) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1548545 + ... + 1549823.

It is an arithmetic number, because the mean of its divisors is an integer number (27132000).

Almost surely, 2^1981406336 is an apocalyptic number.

1981406336 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 1981406336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2604672000).

1981406336 is an abundant number, since it is smaller than the sum of its proper divisors (3227937664).

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

1981406336 is a wasteful number, since it uses less digits than its factorization.

1981406336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339 (or 1320 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 1981406336 is about 44512.9906431819. The cubic root of 1981406336 is about 1256.0044626398.

The spelling of 1981406336 in words is "one billion, nine hundred eighty-one million, four hundred six thousand, three hundred thirty-six".