71720240407 has 4 divisors (see below), whose sum is σ = 75939078096. Its totient is φ = 67501402720.

The previous prime is 71720240363. The next prime is 71720240419. The reversal of 71720240407 is 70404202717.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70404202717 = 397 ⋅177340561.

It is a cyclic number.

It is not a de Polignac number, because 71720240407 - 2²⁷ = 71586022679 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 (71720240497) 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, 2109418819 + ... + 2109418852.

It is an arithmetic number, because the mean of its divisors is an integer number (18984769524).

Almost surely, 2^71720240407 is an apocalyptic number.

71720240407 is a deficient number, since it is larger than the sum of its proper divisors (4218837689).

71720240407 is a wasteful number, since it uses less digits than its factorization.

71720240407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4218837688.

The product of its (nonzero) digits is 21952, while the sum is 34.

The spelling of 71720240407 in words is "seventy-one billion, seven hundred twenty million, two hundred forty thousand, four hundred seven".