71989920 has 72 divisors (see below), whose sum is σ = 245670516. Its totient is φ = 19196928.

The previous prime is 71989909. The next prime is 71989933. The reversal of 71989920 is 2998917.

It can be written as a sum of positive squares in 2 ways, for example, as 71978256 + 11664 = 8484^2 + 108^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23557 + ... + 26436.

Almost surely, 2^71989920 is an apocalyptic number.

It is an amenable number.

71989920 is an abundant number, since it is smaller than the sum of its proper divisors (173680596).

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

71989920 is a wasteful number, since it uses less digits than its factorization.

71989920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50014 (or 50003 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 71989920 is about 8484.6873837520. The cubic root of 71989920 is about 415.9973495886.

The spelling of 71989920 in words is "seventy-one million, nine hundred eighty-nine thousand, nine hundred twenty".