9971531 has 4 divisors (see below), whose sum is σ = 10140600. Its totient is φ = 9802464.

The previous prime is 9971519. The next prime is 9971539. The reversal of 9971531 is 1351799.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 9971531 - 2¹⁸ = 9709387 is a prime.

It is a super-2 number, since 2×9971531² = 198862860967922, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9971491 and 9971500.

It is not an unprimeable number, because it can be changed into a prime (9971539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84446 + ... + 84563.

It is an arithmetic number, because the mean of its divisors is an integer number (2535150).

Almost surely, 2^9971531 is an apocalyptic number.

9971531 is a deficient number, since it is larger than the sum of its proper divisors (169069).

9971531 is a wasteful number, since it uses less digits than its factorization.

9971531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169068.

The product of its digits is 8505, while the sum is 35.

The square root of 9971531 is about 3157.7731077454. The cubic root of 9971531 is about 215.2388260101.

It can be divided in two parts, 9971 and 531, that multiplied together give a square (5294601 = 2301²).

The spelling of 9971531 in words is "nine million, nine hundred seventy-one thousand, five hundred thirty-one".