81512207 has 16 divisors (see below), whose sum is σ = 97605120. Its totient is φ = 66556512.

The previous prime is 81512201. The next prime is 81512231. The reversal of 81512207 is 70221518.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81512207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81512201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44669 + ... + 46457.

It is an arithmetic number, because the mean of its divisors is an integer number (6100320).

Almost surely, 2^81512207 is an apocalyptic number.

81512207 is a deficient number, since it is larger than the sum of its proper divisors (16092913).

81512207 is a wasteful number, since it uses less digits than its factorization.

81512207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 81512207 is about 9028.4111005204. The cubic root of 81512207 is about 433.5849681811.

The spelling of 81512207 in words is "eighty-one million, five hundred twelve thousand, two hundred seven".