81381452 has 24 divisors (see below), whose sum is σ = 148925952. Its totient is φ = 38838800.

The previous prime is 81381451. The next prime is 81381467. The reversal of 81381452 is 25418318.

It is not an unprimeable number, because it can be changed into a prime (81381451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83327 + ... + 84297.

It is an arithmetic number, because the mean of its divisors is an integer number (6205248).

Almost surely, 2^81381452 is an apocalyptic number.

It is an amenable number.

81381452 is a deficient number, since it is larger than the sum of its proper divisors (67544500).

81381452 is a wasteful number, since it uses less digits than its factorization.

81381452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1909 (or 1907 counting only the distinct ones).

The product of its digits is 7680, while the sum is 32.

The square root of 81381452 is about 9021.1668868279. The cubic root of 81381452 is about 433.3530039723.

The spelling of 81381452 in words is "eighty-one million, three hundred eighty-one thousand, four hundred fifty-two".