71521520 has 40 divisors (see below), whose sum is σ = 190044384. Its totient is φ = 24521472.

The previous prime is 71521519. The next prime is 71521537. The reversal of 71521520 is 2512517.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×71521520² = 10230655646220800, which contains 22 as substring.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 63299 + ... + 64418.

Almost surely, 2^71521520 is an apocalyptic number.

71521520 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

71521520 is an abundant number, since it is smaller than the sum of its proper divisors (118522864).

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

71521520 is a wasteful number, since it uses less digits than its factorization.

71521520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127737 (or 127731 counting only the distinct ones).

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 71521520 is about 8457.0396711852. The cubic root of 71521520 is about 415.0931614531.

The spelling of 71521520 in words is "seventy-one million, five hundred twenty-one thousand, five hundred twenty".