71522821 has 4 divisors (see below), whose sum is σ = 75287200. Its totient is φ = 67758444.

The previous prime is 71522779. The next prime is 71522827. The reversal of 71522821 is 12822517.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71522821 - 2¹³ = 71514629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71522821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71522827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1882161 + ... + 1882198.

It is an arithmetic number, because the mean of its divisors is an integer number (18821800).

Almost surely, 2^71522821 is an apocalyptic number.

It is an amenable number.

71522821 is a deficient number, since it is larger than the sum of its proper divisors (3764379).

71522821 is a wasteful number, since it uses less digits than its factorization.

71522821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3764378.

The product of its digits is 2240, while the sum is 28.

The square root of 71522821 is about 8457.1165890036. The cubic root of 71522821 is about 415.0956783316.

The spelling of 71522821 in words is "seventy-one million, five hundred twenty-two thousand, eight hundred twenty-one".