989997505 has 16 divisors (see below), whose sum is σ = 1404529920. Its totient is φ = 655445952.

The previous prime is 989997497. The next prime is 989997509. The reversal of 989997505 is 505799989.

It is a happy number.

It is not a de Polignac number, because 989997505 - 2³ = 989997497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (989997509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 486669 + ... + 488698.

It is an arithmetic number, because the mean of its divisors is an integer number (87783120).

Almost surely, 2^989997505 is an apocalyptic number.

It is an amenable number.

989997505 is a deficient number, since it is larger than the sum of its proper divisors (414532415).

989997505 is a wasteful number, since it uses less digits than its factorization.

989997505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975408.

The product of its (nonzero) digits is 9185400, while the sum is 61.

The square root of 989997505 is about 31464.2257969269. The cubic root of 989997505 is about 996.6546561542.

The spelling of 989997505 in words is "nine hundred eighty-nine million, nine hundred ninety-seven thousand, five hundred five".