81451225 has 6 divisors (see below), whose sum is σ = 100999550. Its totient is φ = 65160960.

The previous prime is 81451219. The next prime is 81451241. The reversal of 81451225 is 52215418.

It can be written as a sum of positive squares in 3 ways, for example, as 18344089 + 63107136 = 4283^2 + 7944^2 .

It is not a de Polignac number, because 81451225 - 2³ = 81451217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81451193 and 81451202.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1629000 + ... + 1629049.

Almost surely, 2^81451225 is an apocalyptic number.

It is an amenable number.

81451225 is a deficient number, since it is larger than the sum of its proper divisors (19548325).

81451225 is a wasteful number, since it uses less digits than its factorization.

81451225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3258059 (or 3258054 counting only the distinct ones).

The product of its digits is 3200, while the sum is 28.

The square root of 81451225 is about 9025.0332409360. The cubic root of 81451225 is about 433.4768147482.

The spelling of 81451225 in words is "eighty-one million, four hundred fifty-one thousand, two hundred twenty-five".