81512053 has 16 divisors (see below), whose sum is σ = 96053760. Its totient is φ = 67723776.

The previous prime is 81512009. The next prime is 81512117. The reversal of 81512053 is 35021518.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81512053 - 2⁹ = 81511541 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 (81515053) 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, 34725 + ... + 36997.

It is an arithmetic number, because the mean of its divisors is an integer number (6003360).

Almost surely, 2^81512053 is an apocalyptic number.

It is an amenable number.

81512053 is a deficient number, since it is larger than the sum of its proper divisors (14541707).

81512053 is a wasteful number, since it uses less digits than its factorization.

81512053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2436.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 81512053 is about 9028.4025718839. The cubic root of 81512053 is about 433.5846951254.

The spelling of 81512053 in words is "eighty-one million, five hundred twelve thousand, fifty-three".