81758907 has 6 divisors (see below), whose sum is σ = 118096212. Its totient is φ = 54505932.

The previous prime is 81758891. The next prime is 81758923. The reversal of 81758907 is 70985718.

It is an interprime number because it is at equal distance from previous prime (81758891) and next prime (81758923).

It is not a de Polignac number, because 81758907 - 2⁴ = 81758891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81758927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4542153 + ... + 4542170.

It is an arithmetic number, because the mean of its divisors is an integer number (19682702).

Almost surely, 2^81758907 is an apocalyptic number.

81758907 is a deficient number, since it is larger than the sum of its proper divisors (36337305).

81758907 is a wasteful number, since it uses less digits than its factorization.

81758907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9084329 (or 9084326 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 81758907 is about 9042.0632048222. The cubic root of 81758907 is about 434.0219484607.

The spelling of 81758907 in words is "eighty-one million, seven hundred fifty-eight thousand, nine hundred seven".