81964067015 has 4 divisors (see below), whose sum is σ = 98356880424. Its totient is φ = 65571253608.

The previous prime is 81964066981. The next prime is 81964067113. The reversal of 81964067015 is 51076046918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81964067015 - 2¹⁶ = 81964001479 is a prime.

It is a super-2 number, since 2×81964067015² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8196406697 + ... + 8196406706.

It is an arithmetic number, because the mean of its divisors is an integer number (24589220106).

Almost surely, 2^81964067015 is an apocalyptic number.

81964067015 is a deficient number, since it is larger than the sum of its proper divisors (16392813409).

81964067015 is a wasteful number, since it uses less digits than its factorization.

81964067015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16392813408.

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 81964067015 in words is "eighty-one billion, nine hundred sixty-four million, sixty-seven thousand, fifteen".