81948249 has 6 divisors (see below), whose sum is σ = 118369706. Its totient is φ = 54632160.

The previous prime is 81948247. The next prime is 81948277. The reversal of 81948249 is 94284918.

It can be written as a sum of positive squares in only one way, i.e., 55353600 + 26594649 = 7440^2 + 5157^2 .

It is not a de Polignac number, because 81948249 - 2¹ = 81948247 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81948247) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4552672 + ... + 4552689.

Almost surely, 2^81948249 is an apocalyptic number.

It is an amenable number.

81948249 is a deficient number, since it is larger than the sum of its proper divisors (36421457).

81948249 is a wasteful number, since it uses less digits than its factorization.

81948249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9105367 (or 9105364 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 81948249 is about 9052.5272161977. The cubic root of 81948249 is about 434.3567345217.

The spelling of 81948249 in words is "eighty-one million, nine hundred forty-eight thousand, two hundred forty-nine".