1913653921 has 2 divisors, whose sum is σ = 1913653922. Its totient is φ = 1913653920.

The previous prime is 1913653919. The next prime is 1913653957. The reversal of 1913653921 is 1293563191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1620867600 + 292786321 = 40260^2 + 17111^2 .

It is a cyclic number.

It is not a de Polignac number, because 1913653921 - 2¹ = 1913653919 is a prime.

Together with 1913653919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1913653121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 956826960 + 956826961.

It is an arithmetic number, because the mean of its divisors is an integer number (956826961).

Almost surely, 2^1913653921 is an apocalyptic number.

It is an amenable number.

1913653921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1913653921 is an equidigital number, since it uses as much as digits as its factorization.

1913653921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43740, while the sum is 40.

The square root of 1913653921 is about 43745.3302764992. The cubic root of 1913653921 is about 1241.5221337665.

The spelling of 1913653921 in words is "one billion, nine hundred thirteen million, six hundred fifty-three thousand, nine hundred twenty-one".