1321487729 has 2 divisors, whose sum is σ = 1321487730. Its totient is φ = 1321487728.

The previous prime is 1321487669. The next prime is 1321487749. The reversal of 1321487729 is 9277841231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1147854400 + 173633329 = 33880^2 + 13177^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321487729 - 2¹² = 1321483633 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321487729.

It is not a weakly prime, because it can be changed into another prime (1321487749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660743864 + 660743865.

It is an arithmetic number, because the mean of its divisors is an integer number (660743865).

Almost surely, 2^1321487729 is an apocalyptic number.

It is an amenable number.

1321487729 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321487729 is an equidigital number, since it uses as much as digits as its factorization.

1321487729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 44.

The square root of 1321487729 is about 36352.2726799852. The cubic root of 1321487729 is about 1097.3732722086.

The spelling of 1321487729 in words is "one billion, three hundred twenty-one million, four hundred eighty-seven thousand, seven hundred twenty-nine".