10001989440 has 504 divisors, whose sum is σ = 37333059192. Its totient is φ = 2456616960.

The previous prime is 10001989409. The next prime is 10001989469. The reversal of 10001989440 is 4498910001.

It can be written as a sum of positive squares in 12 ways, for example, as 219988224 + 9782001216 = 14832^2 + 98904^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 10001989395 and 10001989404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 50771422 + ... + 50771618.

Almost surely, 2^10001989440 is an apocalyptic number.

10001989440 is a gapful number since it is divisible by the number (10) 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 10001989440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18666529596).

10001989440 is an abundant number, since it is smaller than the sum of its proper divisors (27331069752).

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

10001989440 is a wasteful number, since it uses less digits than its factorization.

10001989440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 10001989440 in words is "ten billion, one million, nine hundred eighty-nine thousand, four hundred forty".