81382609 has 8 divisors (see below), whose sum is σ = 101464128. Its totient is φ = 63414960.

The previous prime is 81382583. The next prime is 81382619. The reversal of 81382609 is 90628318.

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

It is not a de Polignac number, because 81382609 - 2⁵ = 81382577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81382619) 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, 528382 + ... + 528535.

It is an arithmetic number, because the mean of its divisors is an integer number (12683016).

Almost surely, 2^81382609 is an apocalyptic number.

It is an amenable number.

81382609 is a deficient number, since it is larger than the sum of its proper divisors (20081519).

81382609 is a wasteful number, since it uses less digits than its factorization.

81382609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056935.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 81382609 is about 9021.2310135591. The cubic root of 81382609 is about 433.3550576223.

The spelling of 81382609 in words is "eighty-one million, three hundred eighty-two thousand, six hundred nine".