989643831 has 16 divisors (see below), whose sum is σ = 1524158208. Its totient is φ = 564502400.

The previous prime is 989643827. The next prime is 989643833. The reversal of 989643831 is 138346989.

It is not a de Polignac number, because 989643831 - 2² = 989643827 is a prime.

It is a super-2 number, since 2×989643831² = 1958789824472713122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989643833) 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, 881475 + ... + 882596.

It is an arithmetic number, because the mean of its divisors is an integer number (95259888).

Almost surely, 2^989643831 is an apocalyptic number.

989643831 is a deficient number, since it is larger than the sum of its proper divisors (534514377).

989643831 is a wasteful number, since it uses less digits than its factorization.

989643831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1764102.

The product of its digits is 1119744, while the sum is 51.

The square root of 989643831 is about 31458.6050390032. The cubic root of 989643831 is about 996.5359579349.

The spelling of 989643831 in words is "nine hundred eighty-nine million, six hundred forty-three thousand, eight hundred thirty-one".