1916621849 has 2 divisors, whose sum is σ = 1916621850. Its totient is φ = 1916621848.

The previous prime is 1916621801. The next prime is 1916621873. The reversal of 1916621849 is 9481266191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1700737600 + 215884249 = 41240^2 + 14693^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1916621849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1916627849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 958310924 + 958310925.

It is an arithmetic number, because the mean of its divisors is an integer number (958310925).

Almost surely, 2^1916621849 is an apocalyptic number.

It is an amenable number.

1916621849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1916621849 is an equidigital number, since it uses as much as digits as its factorization.

1916621849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 186624, while the sum is 47.

The square root of 1916621849 is about 43779.2399317302. The cubic root of 1916621849 is about 1242.1636369111.

The spelling of 1916621849 in words is "one billion, nine hundred sixteen million, six hundred twenty-one thousand, eight hundred forty-nine".