81489698 has 4 divisors (see below), whose sum is σ = 122234550. Its totient is φ = 40744848.

The previous prime is 81489691. The next prime is 81489701. The reversal of 81489698 is 89698418.

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

It can be written as a sum of positive squares in only one way, i.e., 55100929 + 26388769 = 7423^2 + 5137^2 .

It is not an unprimeable number, because it can be changed into a prime (81489691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20372423 + ... + 20372426.

Almost surely, 2^81489698 is an apocalyptic number.

81489698 is a deficient number, since it is larger than the sum of its proper divisors (40744852).

81489698 is a wasteful number, since it uses less digits than its factorization.

81489698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40744851.

The product of its digits is 995328, while the sum is 53.

The square root of 81489698 is about 9027.1644495932. The cubic root of 81489698 is about 433.5450540672.

The spelling of 81489698 in words is "eighty-one million, four hundred eighty-nine thousand, six hundred ninety-eight".