81382801 has 4 divisors (see below), whose sum is σ = 81660852. Its totient is φ = 81104752.

The previous prime is 81382753. The next prime is 81382811. The reversal of 81382801 is 10828318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10828318 = 2 ⋅5414159.

It can be written as a sum of positive squares in 2 ways, for example, as 45968400 + 35414401 = 6780^2 + 5951^2 .

It is a cyclic number.

It is not a de Polignac number, because 81382801 - 2⁷ = 81382673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81382811) 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, 138586 + ... + 139171.

It is an arithmetic number, because the mean of its divisors is an integer number (20415213).

Almost surely, 2^81382801 is an apocalyptic number.

It is an amenable number.

81382801 is a deficient number, since it is larger than the sum of its proper divisors (278051).

81382801 is a wasteful number, since it uses less digits than its factorization.

81382801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278050.

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 81382801 is about 9021.2416551160. The cubic root of 81382801 is about 433.3553984162.

The spelling of 81382801 in words is "eighty-one million, three hundred eighty-two thousand, eight hundred one".