71491999 has 2 divisors, whose sum is σ = 71492000. Its totient is φ = 71491998.

The previous prime is 71491997. The next prime is 71492023. The reversal of 71491999 is 99919417.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 71491999 - 2¹ = 71491997 is a prime.

It is a super-2 number, since 2×71491999² = 10222211842032002, which contains 22 as substring.

Together with 71491997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71491997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35745999 + 35746000.

It is an arithmetic number, because the mean of its divisors is an integer number (35746000).

Almost surely, 2^71491999 is an apocalyptic number.

71491999 is a deficient number, since it is larger than the sum of its proper divisors (1).

71491999 is an equidigital number, since it uses as much as digits as its factorization.

71491999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 49.

The square root of 71491999 is about 8455.2941403596. The cubic root of 71491999 is about 415.0360427398.

The spelling of 71491999 in words is "seventy-one million, four hundred ninety-one thousand, nine hundred ninety-nine".