71519821 has 4 divisors (see below), whose sum is σ = 73826944. Its totient is φ = 69212700.

The previous prime is 71519803. The next prime is 71519831. The reversal of 71519821 is 12891517.

It is a happy number.

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 71519821 - 2¹¹ = 71517773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71519831) 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, 1153515 + ... + 1153576.

It is an arithmetic number, because the mean of its divisors is an integer number (18456736).

Almost surely, 2^71519821 is an apocalyptic number.

It is an amenable number.

71519821 is a deficient number, since it is larger than the sum of its proper divisors (2307123).

71519821 is a wasteful number, since it uses less digits than its factorization.

71519821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2307122.

The product of its digits is 5040, while the sum is 34.

The square root of 71519821 is about 8456.9392217279. The cubic root of 71519821 is about 415.0898745689.

The spelling of 71519821 in words is "seventy-one million, five hundred nineteen thousand, eight hundred twenty-one".