1921136897 has 2 divisors, whose sum is σ = 1921136898. Its totient is φ = 1921136896.

The previous prime is 1921136851. The next prime is 1921136927. The reversal of 1921136897 is 7986311291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1514065921 + 407070976 = 38911^2 + 20176^2 .

It is a cyclic number.

It is not a de Polignac number, because 1921136897 - 2⁸ = 1921136641 is a prime.

It is not a weakly prime, because it can be changed into another prime (1921136827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960568448 + 960568449.

It is an arithmetic number, because the mean of its divisors is an integer number (960568449).

Almost surely, 2^1921136897 is an apocalyptic number.

It is an amenable number.

1921136897 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921136897 is an equidigital number, since it uses as much as digits as its factorization.

1921136897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 47.

The square root of 1921136897 is about 43830.7756833027. The cubic root of 1921136897 is about 1243.1382736514.

The spelling of 1921136897 in words is "one billion, nine hundred twenty-one million, one hundred thirty-six thousand, eight hundred ninety-seven".