81552649 has 8 divisors (see below), whose sum is σ = 84061152. Its totient is φ = 79068960.

The previous prime is 81552643. The next prime is 81552671. The reversal of 81552649 is 94625518.

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

It is a cyclic number.

It is not a de Polignac number, because 81552649 - 2¹⁷ = 81421577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81552643) 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, 582 + ... + 12784.

It is an arithmetic number, because the mean of its divisors is an integer number (10507644).

Almost surely, 2^81552649 is an apocalyptic number.

It is an amenable number.

81552649 is a deficient number, since it is larger than the sum of its proper divisors (2508503).

81552649 is a wasteful number, since it uses less digits than its factorization.

81552649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12407.

The product of its digits is 86400, while the sum is 40.

The square root of 81552649 is about 9030.6505302774. The cubic root of 81552649 is about 433.6566635535.

The spelling of 81552649 in words is "eighty-one million, five hundred fifty-two thousand, six hundred forty-nine".