1320898721 has 2 divisors, whose sum is σ = 1320898722. Its totient is φ = 1320898720.

The previous prime is 1320898703. The next prime is 1320898729. The reversal of 1320898721 is 1278980231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1209300625 + 111598096 = 34775^2 + 10564^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320898721 is a prime.

It is a super-2 number, since 2×1320898721² = 3489546862278871682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1320898729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660449360 + 660449361.

It is an arithmetic number, because the mean of its divisors is an integer number (660449361).

Almost surely, 2^1320898721 is an apocalyptic number.

It is an amenable number.

1320898721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320898721 is an equidigital number, since it uses as much as digits as its factorization.

1320898721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 1320898721 is about 36344.1703853589. The cubic root of 1320898721 is about 1097.2102091000.

The spelling of 1320898721 in words is "one billion, three hundred twenty million, eight hundred ninety-eight thousand, seven hundred twenty-one".