1916930221 has 4 divisors (see below), whose sum is σ = 1917023200. Its totient is φ = 1916837244.

The previous prime is 1916930209. The next prime is 1916930227. The reversal of 1916930221 is 1220396191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1220396191 = 7 ⋅174342313.

It is a cyclic number.

It is not a de Polignac number, because 1916930221 - 2¹⁷ = 1916799149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1916930227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201 + ... + 61918.

It is an arithmetic number, because the mean of its divisors is an integer number (479255800).

Almost surely, 2^1916930221 is an apocalyptic number.

It is an amenable number.

1916930221 is a deficient number, since it is larger than the sum of its proper divisors (92979).

1916930221 is an equidigital number, since it uses as much as digits as its factorization.

1916930221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92978.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 1916930221 is about 43782.7616876779. The cubic root of 1916930221 is about 1242.2302520242.

The spelling of 1916930221 in words is "one billion, nine hundred sixteen million, nine hundred thirty thousand, two hundred twenty-one".