1031320921 has 2 divisors, whose sum is σ = 1031320922. Its totient is φ = 1031320920.

The previous prime is 1031320909. The next prime is 1031320967. The reversal of 1031320921 is 1290231301.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 567392400 + 463928521 = 23820^2 + 21539^2 .

It is an emirp because it is prime and its reverse (1290231301) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1031320921 - 2¹⁹ = 1030796633 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1031320892 and 1031320901.

It is not a weakly prime, because it can be changed into another prime (1031320991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 515660460 + 515660461.

It is an arithmetic number, because the mean of its divisors is an integer number (515660461).

Almost surely, 2^1031320921 is an apocalyptic number.

It is an amenable number.

1031320921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1031320921 is an equidigital number, since it uses as much as digits as its factorization.

1031320921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 1031320921 is about 32114.1856661507. The cubic root of 1031320921 is about 1010.3331649304. Note that the first 3 decimals are identical.

The spelling of 1031320921 in words is "one billion, thirty-one million, three hundred twenty thousand, nine hundred twenty-one".