71621520 has 80 divisors (see below), whose sum is σ = 224182080. Its totient is φ = 18913792.

The previous prime is 71621509. The next prime is 71621549. The reversal of 71621520 is 2512617.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×71621520² = 10259284254220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 15 ways as a sum of consecutive naturals, for example, 24286 + ... + 27074.

It is an arithmetic number, because the mean of its divisors is an integer number (2802276).

Almost surely, 2^71621520 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 71621520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112091040).

71621520 is an abundant number, since it is smaller than the sum of its proper divisors (152560560).

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

71621520 is a wasteful number, since it uses less digits than its factorization.

71621520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2912 (or 2906 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 71621520 is about 8462.9498403335. The cubic root of 71621520 is about 415.2865297583.

The spelling of 71621520 in words is "seventy-one million, six hundred twenty-one thousand, five hundred twenty".