1397521 has 2 divisors, whose sum is σ = 1397522. Its totient is φ = 1397520.

The previous prime is 1397509. The next prime is 1397531. The reversal of 1397521 is 1257931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1185921 + 211600 = 1089^2 + 460^2 .

It is an emirp because it is prime and its reverse (1257931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1397521 - 2¹³ = 1389329 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1397521.

It is not a weakly prime, because it can be changed into another prime (1397531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698760 + 698761.

It is an arithmetic number, because the mean of its divisors is an integer number (698761).

2^1397521 is an apocalyptic number.

It is an amenable number.

1397521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1397521 is an equidigital number, since it uses as much as digits as its factorization.

1397521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1890, while the sum is 28.

The square root of 1397521 is about 1182.1679237739. The cubic root of 1397521 is about 111.8028259137.

The spelling of 1397521 in words is "one million, three hundred ninety-seven thousand, five hundred twenty-one".