71099821 has 12 divisors (see below), whose sum is σ = 77336532. Its totient is φ = 65335296.

The previous prime is 71099803. The next prime is 71099827. The reversal of 71099821 is 12899017.

It can be written as a sum of positive squares in 6 ways, for example, as 9084196 + 62015625 = 3014^2 + 7875^2 .

It is not a de Polignac number, because 71099821 - 2⁵ = 71099789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71099827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42615 + ... + 44251.

It is an arithmetic number, because the mean of its divisors is an integer number (6444711).

Almost surely, 2^71099821 is an apocalyptic number.

It is an amenable number.

71099821 is a deficient number, since it is larger than the sum of its proper divisors (6236711).

71099821 is a wasteful number, since it uses less digits than its factorization.

71099821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1920 (or 1907 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 71099821 is about 8432.0709793028. The cubic root of 71099821 is about 414.2757406749.

The spelling of 71099821 in words is "seventy-one million, ninety-nine thousand, eight hundred twenty-one".