81653428 has 6 divisors (see below), whose sum is σ = 142893506. Its totient is φ = 40826712.

The previous prime is 81653423. The next prime is 81653449. The reversal of 81653428 is 82435618.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 59166864 + 22486564 = 7692^2 + 4742^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81653423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10206675 + ... + 10206682.

Almost surely, 2^81653428 is an apocalyptic number.

It is an amenable number.

81653428 is a deficient number, since it is larger than the sum of its proper divisors (61240078).

81653428 is a wasteful number, since it uses less digits than its factorization.

81653428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20413361 (or 20413359 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 81653428 is about 9036.2286380990. The cubic root of 81653428 is about 433.8352209865.

The spelling of 81653428 in words is "eighty-one million, six hundred fifty-three thousand, four hundred twenty-eight".