31561141 has 2 divisors, whose sum is σ = 31561142. Its totient is φ = 31561140.

The previous prime is 31561139. The next prime is 31561171. The reversal of 31561141 is 14116513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30802500 + 758641 = 5550^2 + 871^2 .

It is a cyclic number.

It is not a de Polignac number, because 31561141 - 2¹ = 31561139 is a prime.

It is a super-2 number, since 2×31561141² = 1992211242443762, which contains 22 as substring.

Together with 31561139, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31561121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15780570 + 15780571.

It is an arithmetic number, because the mean of its divisors is an integer number (15780571).

Almost surely, 2^31561141 is an apocalyptic number.

It is an amenable number.

31561141 is a deficient number, since it is larger than the sum of its proper divisors (1).

31561141 is an equidigital number, since it uses as much as digits as its factorization.

31561141 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 22.

The square root of 31561141 is about 5617.9303128465. The cubic root of 31561141 is about 316.0221803851.

Adding to 31561141 its reverse (14116513), we get a palindrome (45677654).

The spelling of 31561141 in words is "thirty-one million, five hundred sixty-one thousand, one hundred forty-one".