989985640 has 32 divisors (see below), whose sum is σ = 2545678080. Its totient is φ = 339423552.

The previous prime is 989985617. The next prime is 989985643. The reversal of 989985640 is 46589989.

It is a super-3 number, since 3×989985640³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (989985643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1767552 + ... + 1768111.

It is an arithmetic number, because the mean of its divisors is an integer number (79552440).

Almost surely, 2^989985640 is an apocalyptic number.

It is an amenable number.

989985640 is an abundant number, since it is smaller than the sum of its proper divisors (1555692440).

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

989985640 is a wasteful number, since it uses less digits than its factorization.

989985640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3535681 (or 3535677 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 58.

The square root of 989985640 is about 31464.0372488974. The cubic root of 989985640 is about 996.6506745432.

The spelling of 989985640 in words is "nine hundred eighty-nine million, nine hundred eighty-five thousand, six hundred forty".