81769253 has 4 divisors (see below), whose sum is σ = 82120428. Its totient is φ = 81418080.

The previous prime is 81769249. The next prime is 81769267. The reversal of 81769253 is 35296718.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11175649 + 70593604 = 3343^2 + 8402^2 .

It is a cyclic number.

It is not a de Polignac number, because 81769253 - 2² = 81769249 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81769253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81769243) 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, 175238 + ... + 175703.

It is an arithmetic number, because the mean of its divisors is an integer number (20530107).

Almost surely, 2^81769253 is an apocalyptic number.

It is an amenable number.

81769253 is a deficient number, since it is larger than the sum of its proper divisors (351175).

81769253 is a wasteful number, since it uses less digits than its factorization.

81769253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351174.

The product of its digits is 90720, while the sum is 41.

The square root of 81769253 is about 9042.6352906661. The cubic root of 81769253 is about 434.0402551376.

The spelling of 81769253 in words is "eighty-one million, seven hundred sixty-nine thousand, two hundred fifty-three".