1016011991 has 2 divisors, whose sum is σ = 1016011992. Its totient is φ = 1016011990.

The previous prime is 1016011979. The next prime is 1016011993. The reversal of 1016011991 is 1991106101.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1991106101) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1661109101 and 1019011661.

It is a cyclic number.

It is not a de Polignac number, because 1016011991 - 2²² = 1011817687 is a prime.

Together with 1016011993, 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 (1016011993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 508005995 + 508005996.

It is an arithmetic number, because the mean of its divisors is an integer number (508005996).

Almost surely, 2^1016011991 is an apocalyptic number.

1016011991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1016011991 is an equidigital number, since it uses as much as digits as its factorization.

1016011991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 29.

The square root of 1016011991 is about 31874.9429960275. The cubic root of 1016011991 is about 1005.3090939730.

The spelling of 1016011991 in words is "one billion, sixteen million, eleven thousand, nine hundred ninety-one".