81758406 has 32 divisors (see below), whose sum is σ = 182252160. Its totient is φ = 24299136.

The previous prime is 81758401. The next prime is 81758407. The reversal of 81758406 is 60485718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81758401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19156 + ... + 23031.

It is an arithmetic number, because the mean of its divisors is an integer number (5695380).

Almost surely, 2^81758406 is an apocalyptic number.

81758406 is an abundant number, since it is smaller than the sum of its proper divisors (100493754).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81758406 is a wasteful number, since it uses less digits than its factorization.

81758406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42228.

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81758406 is about 9042.0355009257. The cubic root of 81758406 is about 434.0210619296.

The spelling of 81758406 in words is "eighty-one million, seven hundred fifty-eight thousand, four hundred six".