1819214981 has 2 divisors, whose sum is σ = 1819214982. Its totient is φ = 1819214980.

The previous prime is 1819214959. The next prime is 1819215019. The reversal of 1819214981 is 1894129181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1812630625 + 6584356 = 42575^2 + 2566^2 .

It is a cyclic number.

It is not a de Polignac number, because 1819214981 - 2¹⁴ = 1819198597 is a prime.

It is a super-2 number, since 2×1819214981² = 6619086294189660722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1819214941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909607490 + 909607491.

It is an arithmetic number, because the mean of its divisors is an integer number (909607491).

Almost surely, 2^1819214981 is an apocalyptic number.

It is an amenable number.

1819214981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1819214981 is an equidigital number, since it uses as much as digits as its factorization.

1819214981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 44.

The square root of 1819214981 is about 42652.2564584806. The cubic root of 1819214981 is about 1220.7535837365.

The spelling of 1819214981 in words is "one billion, eight hundred nineteen million, two hundred fourteen thousand, nine hundred eighty-one".