1021141991 has 2 divisors, whose sum is σ = 1021141992. Its totient is φ = 1021141990.

The previous prime is 1021141949. The next prime is 1021141993. The reversal of 1021141991 is 1991411201.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021141991 is a prime.

Together with 1021141993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021141993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510570995 + 510570996.

It is an arithmetic number, because the mean of its divisors is an integer number (510570996).

Almost surely, 2^1021141991 is an apocalyptic number.

1021141991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021141991 is an equidigital number, since it uses as much as digits as its factorization.

1021141991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 29.

The square root of 1021141991 is about 31955.3124065467. The cubic root of 1021141991 is about 1006.9982407131.

The spelling of 1021141991 in words is "one billion, twenty-one million, one hundred forty-one thousand, nine hundred ninety-one".