31491101 has 2 divisors, whose sum is σ = 31491102. Its totient is φ = 31491100.

The previous prime is 31491079. The next prime is 31491143. The reversal of 31491101 is 10119413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31416025 + 75076 = 5605^2 + 274^2 .

It is an emirp because it is prime and its reverse (10119413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31491101 - 2¹⁰ = 31490077 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31491401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15745550 + 15745551.

It is an arithmetic number, because the mean of its divisors is an integer number (15745551).

Almost surely, 2^31491101 is an apocalyptic number.

It is an amenable number.

31491101 is a deficient number, since it is larger than the sum of its proper divisors (1).

31491101 is an equidigital number, since it uses as much as digits as its factorization.

31491101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 31491101 is about 5611.6932382303. The cubic root of 31491101 is about 315.7882367198.

The spelling of 31491101 in words is "thirty-one million, four hundred ninety-one thousand, one hundred one".