81680224 has 12 divisors (see below), whose sum is σ = 160808004. Its totient is φ = 40840096.

The previous prime is 81680191. The next prime is 81680231. The reversal of 81680224 is 42208618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1276222 + ... + 1276285.

It is an arithmetic number, because the mean of its divisors is an integer number (13400667).

Almost surely, 2^81680224 is an apocalyptic number.

It is an amenable number.

81680224 is a deficient number, since it is larger than the sum of its proper divisors (79127780).

81680224 is a wasteful number, since it uses less digits than its factorization.

81680224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2552517 (or 2552509 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 81680224 is about 9037.7112146826. The cubic root of 81680224 is about 433.8826726671.

The spelling of 81680224 in words is "eighty-one million, six hundred eighty thousand, two hundred twenty-four".