71521920 has 128 divisors (see below), whose sum is σ = 253368000. Its totient is φ = 19067904.

The previous prime is 71521843. The next prime is 71521949. The reversal of 71521920 is 2912517.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15211 + ... + 19349.

Almost surely, 2^71521920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71521920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126684000).

71521920 is an abundant number, since it is smaller than the sum of its proper divisors (181846080).

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

71521920 is a wasteful number, since it uses less digits than its factorization.

71521920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4167 (or 4149 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 71521920 is about 8457.0633200893. The cubic root of 71521920 is about 415.0939352852.

The spelling of 71521920 in words is "seventy-one million, five hundred twenty-one thousand, nine hundred twenty".