1913407921 has 2 divisors, whose sum is σ = 1913407922. Its totient is φ = 1913407920.

The previous prime is 1913407871. The next prime is 1913407957. The reversal of 1913407921 is 1297043191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1228853025 + 684554896 = 35055^2 + 26164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1913407921 is a prime.

It is a super-2 number, since 2×1913407921² = 7322259744291084482, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1913407981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 956703960 + 956703961.

It is an arithmetic number, because the mean of its divisors is an integer number (956703961).

Almost surely, 2^1913407921 is an apocalyptic number.

It is an amenable number.

1913407921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1913407921 is an equidigital number, since it uses as much as digits as its factorization.

1913407921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 1913407921 is about 43742.5184574460. The cubic root of 1913407921 is about 1241.4689323091.

The spelling of 1913407921 in words is "one billion, nine hundred thirteen million, four hundred seven thousand, nine hundred twenty-one".