71521437 has 8 divisors (see below), whose sum is σ = 102697504. Its totient is φ = 44013168.

The previous prime is 71521423. The next prime is 71521459. The reversal of 71521437 is 73412517.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 71521437 - 2¹⁰ = 71520413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71521537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 916903 + ... + 916980.

It is an arithmetic number, because the mean of its divisors is an integer number (12837188).

Almost surely, 2^71521437 is an apocalyptic number.

It is an amenable number.

71521437 is a deficient number, since it is larger than the sum of its proper divisors (31176067).

71521437 is a wasteful number, since it uses less digits than its factorization.

71521437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1833899.

The product of its digits is 5880, while the sum is 30.

The square root of 71521437 is about 8457.0347640293. The cubic root of 71521437 is about 415.0930008825.

The spelling of 71521437 in words is "seventy-one million, five hundred twenty-one thousand, four hundred thirty-seven".