31381601 has 2 divisors, whose sum is σ = 31381602. Its totient is φ = 31381600.

The previous prime is 31381583. The next prime is 31381621. The reversal of 31381601 is 10618313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29691601 + 1690000 = 5449^2 + 1300^2 .

It is an emirp because it is prime and its reverse (10618313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31381601 - 2¹⁸ = 31119457 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31381621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15690800 + 15690801.

It is an arithmetic number, because the mean of its divisors is an integer number (15690801).

Almost surely, 2^31381601 is an apocalyptic number.

It is an amenable number.

31381601 is a deficient number, since it is larger than the sum of its proper divisors (1).

31381601 is an equidigital number, since it uses as much as digits as its factorization.

31381601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 31381601 is about 5601.9283287097. The cubic root of 31381601 is about 315.4217949076.

Adding to 31381601 its reverse (10618313), we get a palindrome (41999914).

The spelling of 31381601 in words is "thirty-one million, three hundred eighty-one thousand, six hundred one".