71784025209 has 48 divisors (see below), whose sum is σ = 114084406800. Its totient is φ = 43227537408.

The previous prime is 71784025151. The next prime is 71784025217. The reversal of 71784025209 is 90252048717.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 34892372025 + 36891653184 = 186795^2 + 192072^2 .

It is not a de Polignac number, because 71784025209 - 2⁷ = 71784025081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71784025279) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 974527 + ... + 1045595.

It is an arithmetic number, because the mean of its divisors is an integer number (2376758475).

Almost surely, 2^71784025209 is an apocalyptic number.

It is an amenable number.

71784025209 is a deficient number, since it is larger than the sum of its proper divisors (42300381591).

71784025209 is a wasteful number, since it uses less digits than its factorization.

71784025209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71274 (or 71271 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 45.

The spelling of 71784025209 in words is "seventy-one billion, seven hundred eighty-four million, twenty-five thousand, two hundred nine".