81007275 has 12 divisors (see below), whose sum is σ = 133932152. Its totient is φ = 43203840.

The previous prime is 81007271. The next prime is 81007291. The reversal of 81007275 is 57270018.

It is a happy number.

It is not a de Polignac number, because 81007275 - 2² = 81007271 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81007271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 539974 + ... + 540123.

Almost surely, 2^81007275 is an apocalyptic number.

81007275 is a deficient number, since it is larger than the sum of its proper divisors (52924877).

81007275 is a wasteful number, since it uses less digits than its factorization.

81007275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080110 (or 1080105 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 81007275 is about 9000.4041575920. The cubic root of 81007275 is about 432.6878242422.

The spelling of 81007275 in words is "eighty-one million, seven thousand, two hundred seventy-five".