81924939145 has 8 divisors (see below), whose sum is σ = 112354202304. Its totient is φ = 56177101104.

The previous prime is 81924939137. The next prime is 81924939197. The reversal of 81924939145 is 54193942918.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81924939145 - 2³ = 81924939137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1170356239 + ... + 1170356308.

It is an arithmetic number, because the mean of its divisors is an integer number (14044275288).

Almost surely, 2^81924939145 is an apocalyptic number.

It is an amenable number.

81924939145 is a deficient number, since it is larger than the sum of its proper divisors (30429263159).

81924939145 is a wasteful number, since it uses less digits than its factorization.

81924939145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2340712559.

The product of its digits is 2799360, while the sum is 55.

The spelling of 81924939145 in words is "eighty-one billion, nine hundred twenty-four million, nine hundred thirty-nine thousand, one hundred forty-five".