9961531 has 2 divisors, whose sum is σ = 9961532. Its totient is φ = 9961530.

The previous prime is 9961519. The next prime is 9961543. The reversal of 9961531 is 1351699.

It is a balanced prime because it is at equal distance from previous prime (9961519) and next prime (9961543).

It is a cyclic number.

It is not a de Polignac number, because 9961531 - 2¹⁷ = 9830459 is a prime.

It is a super-2 number, since 2×9961531² = 198464199727922, which contains 22 as substring.

9961531 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (9961631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4980765 + 4980766.

It is an arithmetic number, because the mean of its divisors is an integer number (4980766).

Almost surely, 2^9961531 is an apocalyptic number.

9961531 is a deficient number, since it is larger than the sum of its proper divisors (1).

9961531 is an equidigital number, since it uses as much as digits as its factorization.

9961531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7290, while the sum is 34.

The square root of 9961531 is about 3156.1893162483. The cubic root of 9961531 is about 215.1668508316.

The spelling of 9961531 in words is "nine million, nine hundred sixty-one thousand, five hundred thirty-one".