1321573817 has 2 divisors, whose sum is σ = 1321573818. Its totient is φ = 1321573816.

The previous prime is 1321573793. The next prime is 1321573831. The reversal of 1321573817 is 7183751231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1288522816 + 33051001 = 35896^2 + 5749^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321573817 - 2⁶ = 1321573753 is a prime.

It is a super-4 number, since 4×1321573817⁴ (a number of 38 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (1321573867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660786908 + 660786909.

It is an arithmetic number, because the mean of its divisors is an integer number (660786909).

Almost surely, 2^1321573817 is an apocalyptic number.

It is an amenable number.

1321573817 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321573817 is an equidigital number, since it uses as much as digits as its factorization.

1321573817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 38.

The square root of 1321573817 is about 36353.4567407282. The cubic root of 1321573817 is about 1097.3971010637.

The spelling of 1321573817 in words is "one billion, three hundred twenty-one million, five hundred seventy-three thousand, eight hundred seventeen".