99991481 has 2 divisors, whose sum is σ = 99991482. Its totient is φ = 99991480.

The previous prime is 99991447. The next prime is 99991499. The reversal of 99991481 is 18419999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 98406400 + 1585081 = 9920^2 + 1259^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99991481 is a prime.

It is a super-3 number, since 3×99991481³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99991081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49995740 + 49995741.

It is an arithmetic number, because the mean of its divisors is an integer number (49995741).

Almost surely, 2^99991481 is an apocalyptic number.

It is an amenable number.

99991481 is a deficient number, since it is larger than the sum of its proper divisors (1).

99991481 is an equidigital number, since it uses as much as digits as its factorization.

99991481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 50.

The square root of 99991481 is about 9999.5740409279. The cubic root of 99991481 is about 464.1457024219.

The spelling of 99991481 in words is "ninety-nine million, nine hundred ninety-one thousand, four hundred eighty-one".