81275505 has 8 divisors (see below), whose sum is σ = 130040832. Its totient is φ = 43346928.

The previous prime is 81275503. The next prime is 81275507. The reversal of 81275505 is 50557218.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81275503) and next prime (81275507).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81275505 - 2¹ = 81275503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81275501) 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, 2709169 + ... + 2709198.

It is an arithmetic number, because the mean of its divisors is an integer number (16255104).

Almost surely, 2^81275505 is an apocalyptic number.

It is an amenable number.

81275505 is a deficient number, since it is larger than the sum of its proper divisors (48765327).

81275505 is a wasteful number, since it uses less digits than its factorization.

81275505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5418375.

The product of its (nonzero) digits is 14000, while the sum is 33.

The square root of 81275505 is about 9015.2928405016. The cubic root of 81275505 is about 433.1648677823.

The spelling of 81275505 in words is "eighty-one million, two hundred seventy-five thousand, five hundred five".