1381804561 has 2 divisors, whose sum is σ = 1381804562. Its totient is φ = 1381804560.

The previous prime is 1381804519. The next prime is 1381804573. The reversal of 1381804561 is 1654081831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1380865600 + 938961 = 37160^2 + 969^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381804561 - 2¹⁵ = 1381771793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1381804561.

It is not a weakly prime, because it can be changed into another prime (1381804661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690902280 + 690902281.

It is an arithmetic number, because the mean of its divisors is an integer number (690902281).

Almost surely, 2^1381804561 is an apocalyptic number.

It is an amenable number.

1381804561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381804561 is an equidigital number, since it uses as much as digits as its factorization.

1381804561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 1381804561 is about 37172.6318815335. The cubic root of 1381804561 is about 1113.8213559512.

The spelling of 1381804561 in words is "one billion, three hundred eighty-one million, eight hundred four thousand, five hundred sixty-one".