81090993075 has 12 divisors (see below), whose sum is σ = 134070442008. Its totient is φ = 43248529600.

The previous prime is 81090993047. The next prime is 81090993077. The reversal of 81090993075 is 57039909018.

It is a happy number.

It is not a de Polignac number, because 81090993075 - 2⁷ = 81090992947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81090993077) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 540606546 + ... + 540606695.

It is an arithmetic number, because the mean of its divisors is an integer number (11172536834).

Almost surely, 2^81090993075 is an apocalyptic number.

81090993075 is a deficient number, since it is larger than the sum of its proper divisors (52979448933).

81090993075 is a wasteful number, since it uses less digits than its factorization.

81090993075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1081213254 (or 1081213249 counting only the distinct ones).

The product of its (nonzero) digits is 612360, while the sum is 51.

The spelling of 81090993075 in words is "eighty-one billion, ninety million, nine hundred ninety-three thousand, seventy-five".