81950418 has 48 divisors (see below), whose sum is σ = 195054912. Its totient is φ = 24660000.

The previous prime is 81950411. The next prime is 81950419. The reversal of 81950418 is 81405918.

It is not an unprimeable number, because it can be changed into a prime (81950411) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28528 + ... + 31268.

It is an arithmetic number, because the mean of its divisors is an integer number (4063644).

Almost surely, 2^81950418 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81950418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97527456).

81950418 is an abundant number, since it is smaller than the sum of its proper divisors (113104494).

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

81950418 is a wasteful number, since it uses less digits than its factorization.

81950418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2911 (or 2908 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 81950418 is about 9052.6470162047. The cubic root of 81950418 is about 434.3605666615.

The spelling of 81950418 in words is "eighty-one million, nine hundred fifty thousand, four hundred eighteen".