81532071215 has 8 divisors (see below), whose sum is σ = 111815412000. Its totient is φ = 55907705952.

The previous prime is 81532071211. The next prime is 81532071227. The reversal of 81532071215 is 51217023518.

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

It is not a de Polignac number, because 81532071215 - 2² = 81532071211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35), and also a Moran number because the ratio is a prime number: 2329487749 = 81532071215 / (8 + 1 + 5 + 3 + 2 + 0 + 7 + 1 + 2 + 1 + 5).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81532071211) 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, 1164743840 + ... + 1164743909.

It is an arithmetic number, because the mean of its divisors is an integer number (13976926500).

Almost surely, 2^81532071215 is an apocalyptic number.

81532071215 is a deficient number, since it is larger than the sum of its proper divisors (30283340785).

81532071215 is a wasteful number, since it uses less digits than its factorization.

81532071215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2329487761.

The product of its (nonzero) digits is 16800, while the sum is 35.

The spelling of 81532071215 in words is "eighty-one billion, five hundred thirty-two million, seventy-one thousand, two hundred fifteen".