71721984 has 88 divisors (see below), whose sum is σ = 196643008. Its totient is φ = 23224320.

The previous prime is 71721977. The next prime is 71722009. The reversal of 71721984 is 48912717.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113349 + ... + 113979.

Almost surely, 2^71721984 is an apocalyptic number.

71721984 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71721984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98321504).

71721984 is an abundant number, since it is smaller than the sum of its proper divisors (124921024).

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

71721984 is a wasteful number, since it uses less digits than its factorization.

71721984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691 (or 673 counting only the distinct ones).

The product of its digits is 28224, while the sum is 39.

The square root of 71721984 is about 8468.8832793940. The cubic root of 71721984 is about 415.4806141317.

The spelling of 71721984 in words is "seventy-one million, seven hundred twenty-one thousand, nine hundred eighty-four".