30061991 has 2 divisors, whose sum is σ = 30061992. Its totient is φ = 30061990.

The previous prime is 30061987. The next prime is 30062041. The reversal of 30061991 is 19916003.

It is a weak prime.

It is an emirp because it is prime and its reverse (19916003) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30061991 - 2² = 30061987 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 (30061921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15030995 + 15030996.

It is an arithmetic number, because the mean of its divisors is an integer number (15030996).

Almost surely, 2^30061991 is an apocalyptic number.

30061991 is a deficient number, since it is larger than the sum of its proper divisors (1).

30061991 is an equidigital number, since it uses as much as digits as its factorization.

30061991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 30061991 is about 5482.8816328642. The cubic root of 30061991 is about 310.9371260704.

Adding to 30061991 its reverse (19916003), we get a palindrome (49977994).

The spelling of 30061991 in words is "thirty million, sixty-one thousand, nine hundred ninety-one".