71971920 has 60 divisors (see below), whose sum is σ = 241708116. Its totient is φ = 19192320.

The previous prime is 71971903. The next prime is 71971927. The reversal of 71971920 is 2917917.

It can be written as a sum of positive squares in 2 ways, for example, as 22353984 + 49617936 = 4728^2 + 7044^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71971927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49261 + ... + 50700.

Almost surely, 2^71971920 is an apocalyptic number.

It is an amenable number.

71971920 is an abundant number, since it is smaller than the sum of its proper divisors (169736196).

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

71971920 is a wasteful number, since it uses less digits than its factorization.

71971920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99980 (or 99971 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 36.

The square root of 71971920 is about 8483.6265830127. The cubic root of 71971920 is about 415.9626753988.

The spelling of 71971920 in words is "seventy-one million, nine hundred seventy-one thousand, nine hundred twenty".