81451930 has 32 divisors (see below), whose sum is σ = 177417216. Its totient is φ = 26283264.

The previous prime is 81451927. The next prime is 81451939. The reversal of 81451930 is 3915418.

It is a junction number, because it is equal to n+sod(n) for n = 81451892 and 81451901.

It is not an unprimeable number, because it can be changed into a prime (81451939) 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, 33034 + ... + 35413.

It is an arithmetic number, because the mean of its divisors is an integer number (5544288).

Almost surely, 2^81451930 is an apocalyptic number.

81451930 is an abundant number, since it is smaller than the sum of its proper divisors (95965286).

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

81451930 is a wasteful number, since it uses less digits than its factorization.

81451930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68478.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 81451930 is about 9025.0722988794. The cubic root of 81451930 is about 433.4780653955.

The spelling of 81451930 in words is "eighty-one million, four hundred fifty-one thousand, nine hundred thirty".