1397 has 4 divisors (see below), whose sum is σ = 1536.
Its totient is φ = 1260.
The previous prime is 1381. The next prime is 1399. The reversal of 1397 is 7931.
1397 is nontrivially palindromic in base 2 and base 16.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 1397 - 24 = 1381 is a prime.
It is a Duffinian number.
1397 is an undulating number in base 16.
It is a nialpdrome in base 12 and base 15.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1399) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53 + ... + 74.
It is an arithmetic number, because the mean of its divisors is an integer number (384).
It is an amenable number.
1397 is a deficient number, since it is larger than the sum of its proper divisors (139).
1397 is a wasteful number, since it uses less digits than its factorization.
1397 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 138.
The product of its digits is 189, while the sum is 20.
The square root of 1397 is about 37.3764631821.
The cubic root of 1397 is about 11.1788930711.
The spelling of 1397 in words is "one thousand, three hundred ninety-seven".