1378561 has 2 divisors, whose sum is σ = 1378562. Its totient is φ = 1378560.

The previous prime is 1378541. The next prime is 1378567. The reversal of 1378561 is 1658731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1299600 + 78961 = 1140^2 + 281^2 .

It is a cyclic number.

It is not a de Polignac number, because 1378561 - 2⁵ = 1378529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1378567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 689280 + 689281.

It is an arithmetic number, because the mean of its divisors is an integer number (689281).

2^1378561 is an apocalyptic number.

It is an amenable number.

1378561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1378561 is an equidigital number, since it uses as much as digits as its factorization.

1378561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 1378561 is about 1174.1213736237. The cubic root of 1378561 is about 111.2949168455.

The spelling of 1378561 in words is "one million, three hundred seventy-eight thousand, five hundred sixty-one".