2021299991 has 2 divisors, whose sum is σ = 2021299992. Its totient is φ = 2021299990.

The previous prime is 2021299981. The next prime is 2021300003. The reversal of 2021299991 is 1999921202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021299991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021299981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010649995 + 1010649996.

It is an arithmetic number, because the mean of its divisors is an integer number (1010649996).

Almost surely, 2^2021299991 is an apocalyptic number.

2021299991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021299991 is an equidigital number, since it uses as much as digits as its factorization.

2021299991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 2021299991 is about 44958.8699924720. The cubic root of 2021299991 is about 1264.3779828743.

The spelling of 2021299991 in words is "two billion, twenty-one million, two hundred ninety-nine thousand, nine hundred ninety-one".