1821213983 has 2 divisors, whose sum is σ = 1821213984. Its totient is φ = 1821213982.

The previous prime is 1821213943. The next prime is 1821214013. The reversal of 1821213983 is 3893121281.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1821213983 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1821213913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910606991 + 910606992.

It is an arithmetic number, because the mean of its divisors is an integer number (910606992).

Almost surely, 2^1821213983 is an apocalyptic number.

1821213983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1821213983 is an equidigital number, since it uses as much as digits as its factorization.

1821213983 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 38.

The square root of 1821213983 is about 42675.6837437902. The cubic root of 1821213983 is about 1221.2005522748.

The spelling of 1821213983 in words is "one billion, eight hundred twenty-one million, two hundred thirteen thousand, nine hundred eighty-three".