31535721889 has 27 divisors (see below), whose sum is σ = 38383531473. Its totient is φ = 25831933512.

The previous prime is 31535721863. The next prime is 31535721907. The reversal of 31535721889 is 98812753513.

The square root of 31535721889 is 177583.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 31535721889 - 2⁵ = 31535721857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31535721809) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 28590312 + ... + 28591414.

Almost surely, 2^31535721889 is an apocalyptic number.

31535721889 is the 177583-rd square number.

31535721889 is the 88792-nd centered octagonal number.

It is an amenable number.

31535721889 is a deficient number, since it is larger than the sum of its proper divisors (6847809584).

31535721889 is an frugal number, since it uses more digits than its factorization.

31535721889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2266 (or 1133 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 52.

It can be divided in two parts, 31535 and 721889, that added together give a square (753424 = 868²).

The spelling of 31535721889 in words is "thirty-one billion, five hundred thirty-five million, seven hundred twenty-one thousand, eight hundred eighty-nine".