81946625063 has 4 divisors (see below), whose sum is σ = 82712481480. Its totient is φ = 81180768648.

The previous prime is 81946625051. The next prime is 81946625071. The reversal of 81946625063 is 36052664918.

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 81946625063 - 2¹² = 81946620967 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 (81946624063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 382928048 + ... + 382928261.

It is an arithmetic number, because the mean of its divisors is an integer number (20678120370).

Almost surely, 2^81946625063 is an apocalyptic number.

81946625063 is a deficient number, since it is larger than the sum of its proper divisors (765856417).

81946625063 is a wasteful number, since it uses less digits than its factorization.

81946625063 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765856416.

The product of its (nonzero) digits is 1866240, while the sum is 50.

The spelling of 81946625063 in words is "eighty-one billion, nine hundred forty-six million, six hundred twenty-five thousand, sixty-three".