31897361 has 8 divisors (see below), whose sum is σ = 33621480. Its totient is φ = 30214912.

The previous prime is 31897339. The next prime is 31897363. The reversal of 31897361 is 16379813.

It can be written as a sum of positive squares in 4 ways, for example, as 5313025 + 26584336 = 2305^2 + 5156^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31897361 - 2¹⁴ = 31880977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31897363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8840 + ... + 11913.

It is an arithmetic number, because the mean of its divisors is an integer number (4202685).

Almost surely, 2^31897361 is an apocalyptic number.

It is an amenable number.

31897361 is a deficient number, since it is larger than the sum of its proper divisors (1724119).

31897361 is a wasteful number, since it uses less digits than its factorization.

31897361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20835.

The product of its digits is 27216, while the sum is 38.

The square root of 31897361 is about 5647.7748715755. The cubic root of 31897361 is about 317.1404108843.

It can be divided in two parts, 318 and 97361, that added together give a palindrome (97679).

The spelling of 31897361 in words is "thirty-one million, eight hundred ninety-seven thousand, three hundred sixty-one".