1921920313 has 2 divisors, whose sum is σ = 1921920314. Its totient is φ = 1921920312.

The previous prime is 1921920307. The next prime is 1921920317. The reversal of 1921920313 is 3130291291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1621833984 + 300086329 = 40272^2 + 17323^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921920313 - 2¹³ = 1921912121 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921920317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960960156 + 960960157.

It is an arithmetic number, because the mean of its divisors is an integer number (960960157).

Almost surely, 2^1921920313 is an apocalyptic number.

It is an amenable number.

1921920313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921920313 is an equidigital number, since it uses as much as digits as its factorization.

1921920313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 1921920313 is about 43839.7115980477. The cubic root of 1921920313 is about 1243.3072295206.

The spelling of 1921920313 in words is "one billion, nine hundred twenty-one million, nine hundred twenty thousand, three hundred thirteen".