81907628799 has 8 divisors (see below), whose sum is σ = 109352190640. Its totient is φ = 54534076416.

The previous prime is 81907628749. The next prime is 81907628801. The reversal of 81907628799 is 99782670918.

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

It is not a de Polignac number, because 81907628799 - 2¹¹ = 81907626751 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 (81907628729) 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, 17749672 + ... + 17754285.

It is an arithmetic number, because the mean of its divisors is an integer number (13669023830).

Almost surely, 2^81907628799 is an apocalyptic number.

81907628799 is a deficient number, since it is larger than the sum of its proper divisors (27444561841).

81907628799 is a wasteful number, since it uses less digits than its factorization.

81907628799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35504729.

The product of its (nonzero) digits is 27433728, while the sum is 66.

The spelling of 81907628799 in words is "eighty-one billion, nine hundred seven million, six hundred twenty-eight thousand, seven hundred ninety-nine".