71728780 has 24 divisors (see below), whose sum is σ = 159491808. Its totient is φ = 27003648.

The previous prime is 71728777. The next prime is 71728799. The reversal of 71728780 is 8782717.

It is a happy number.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105144 + ... + 105823.

It is an arithmetic number, because the mean of its divisors is an integer number (6645492).

Almost surely, 2^71728780 is an apocalyptic number.

It is an amenable number.

71728780 is an abundant number, since it is smaller than the sum of its proper divisors (87763028).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71728780 is a wasteful number, since it uses less digits than its factorization.

71728780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210993 (or 210991 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 40.

The square root of 71728780 is about 8469.2845034277. The cubic root of 71728780 is about 415.4937366404.

The spelling of 71728780 in words is "seventy-one million, seven hundred twenty-eight thousand, seven hundred eighty".