81609253 has 8 divisors (see below), whose sum is σ = 89185536. Its totient is φ = 74059200.

The previous prime is 81609223. The next prime is 81609271. The reversal of 81609253 is 35290618.

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 81609253 - 2¹³ = 81601061 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81609223) 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, 268 + ... + 12778.

It is an arithmetic number, because the mean of its divisors is an integer number (11148192).

Almost surely, 2^81609253 is an apocalyptic number.

It is an amenable number.

81609253 is a deficient number, since it is larger than the sum of its proper divisors (7576283).

81609253 is a wasteful number, since it uses less digits than its factorization.

81609253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13115.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 81609253 is about 9033.7839801492. The cubic root of 81609253 is about 433.7569710446.

The spelling of 81609253 in words is "eighty-one million, six hundred nine thousand, two hundred fifty-three".