1397881 has 2 divisors, whose sum is σ = 1397882. Its totient is φ = 1397880.

The previous prime is 1397873. The next prime is 1397909. The reversal of 1397881 is 1887931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 783225 + 614656 = 885^2 + 784^2 .

It is a cyclic number.

It is not a de Polignac number, because 1397881 - 2³ = 1397873 is a prime.

It is a super-2 number, since 2×1397881² = 3908142580322, which contains 22 as substring.

1397881 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1397881.

It is not a weakly prime, because it can be changed into another prime (1397861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 698940 + 698941.

It is an arithmetic number, because the mean of its divisors is an integer number (698941).

2^1397881 is an apocalyptic number.

It is an amenable number.

1397881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1397881 is an equidigital number, since it uses as much as digits as its factorization.

1397881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 37.

The square root of 1397881 is about 1182.3201766019. The cubic root of 1397881 is about 111.8124251879.

It can be divided in two parts, 1397 and 881, that added together give a triangular number (2278 = T₆₇).

The spelling of 1397881 in words is "one million, three hundred ninety-seven thousand, eight hundred eighty-one".