81450625 has 25 divisors (see below), whose sum is σ = 107435141. Its totient is φ = 61731000.

The previous prime is 81450623. The next prime is 81450631. The reversal of 81450625 is 52605418.

The square root of 81450625 is 9025.

It is a perfect power (a square, a biquadrate), and thus also a powerful number.

It can be written as a sum of positive squares in 2 ways, for example, as 6385729 + 75064896 = 2527^2 + 8664^2 .

It is a tau number, because it is divible by the number of its divisors (25).

It is not a de Polignac number, because 81450625 - 2¹ = 81450623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81450623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 24 ways as a sum of consecutive naturals, for example, 4286866 + ... + 4286884.

Almost surely, 2^81450625 is an apocalyptic number.

81450625 is the 9025-th square number.

81450625 is the 4513-rd centered octagonal number.

It is an amenable number.

81450625 is a deficient number, since it is larger than the sum of its proper divisors (25984516).

81450625 is an frugal number, since it uses more digits than its factorization.

81450625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 24 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

The cubic root of 81450625 is about 433.4757503618.

The spelling of 81450625 in words is "eighty-one million, four hundred fifty thousand, six hundred twenty-five".