81102797 has 4 divisors (see below), whose sum is σ = 83080956. Its totient is φ = 79124640.

The previous prime is 81102751. The next prime is 81102817. The reversal of 81102797 is 79720118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79720118 = 2 ⋅39860059.

It can be written as a sum of positive squares in 2 ways, for example, as 35688676 + 45414121 = 5974^2 + 6739^2 .

It is a cyclic number.

It is not a de Polignac number, because 81102797 - 2¹⁰ = 81101773 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 (81102737) 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, 989018 + ... + 989099.

It is an arithmetic number, because the mean of its divisors is an integer number (20770239).

Almost surely, 2^81102797 is an apocalyptic number.

It is an amenable number.

81102797 is a deficient number, since it is larger than the sum of its proper divisors (1978159).

81102797 is a wasteful number, since it uses less digits than its factorization.

81102797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1978158.

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 81102797 is about 9005.7091336552. The cubic root of 81102797 is about 432.8578294315.

The spelling of 81102797 in words is "eighty-one million, one hundred two thousand, seven hundred ninety-seven".