1819090921 has 8 divisors (see below), whose sum is σ = 1834926464. Its totient is φ = 1803312720.

The previous prime is 1819090919. The next prime is 1819090927. The reversal of 1819090921 is 1290909181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1819090921 - 2¹ = 1819090919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1819090927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50656 + ... + 78766.

It is an arithmetic number, because the mean of its divisors is an integer number (229365808).

Almost surely, 2^1819090921 is an apocalyptic number.

It is an amenable number.

1819090921 is a deficient number, since it is larger than the sum of its proper divisors (15835543).

1819090921 is a wasteful number, since it uses less digits than its factorization.

1819090921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28671.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 1819090921 is about 42650.8021143800. The cubic root of 1819090921 is about 1220.7258336476.

The spelling of 1819090921 in words is "one billion, eight hundred nineteen million, ninety thousand, nine hundred twenty-one".