2021131999 has 2 divisors, whose sum is σ = 2021132000. Its totient is φ = 2021131998.

The previous prime is 2021131979. The next prime is 2021132041. The reversal of 2021131999 is 9991311202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2021131999 - 2⁹ = 2021131487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021131939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010565999 + 1010566000.

It is an arithmetic number, because the mean of its divisors is an integer number (1010566000).

Almost surely, 2^2021131999 is an apocalyptic number.

2021131999 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021131999 is an equidigital number, since it uses as much as digits as its factorization.

2021131999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 2021131999 is about 44957.0016682608. The cubic root of 2021131999 is about 1264.3429540526.

The spelling of 2021131999 in words is "two billion, twenty-one million, one hundred thirty-one thousand, nine hundred ninety-nine".