31840261 has 2 divisors, whose sum is σ = 31840262. Its totient is φ = 31840260.

The previous prime is 31840243. The next prime is 31840271. The reversal of 31840261 is 16204813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17589636 + 14250625 = 4194^2 + 3775^2 .

It is an emirp because it is prime and its reverse (16204813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31840261 - 2⁹ = 31839749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31840271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15920130 + 15920131.

It is an arithmetic number, because the mean of its divisors is an integer number (15920131).

Almost surely, 2^31840261 is an apocalyptic number.

31840261 is the 2524-th centered decagonal number.

It is an amenable number.

31840261 is a deficient number, since it is larger than the sum of its proper divisors (1).

31840261 is an equidigital number, since it uses as much as digits as its factorization.

31840261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 31840261 is about 5642.7175190683. The cubic root of 31840261 is about 316.9510583985.

The spelling of 31840261 in words is "thirty-one million, eight hundred forty thousand, two hundred sixty-one".