71245591531 has 4 divisors (see below), whose sum is σ = 71252046072. Its totient is φ = 71239136992.

The previous prime is 71245591523. The next prime is 71245591561. The reversal of 71245591531 is 13519554217.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71245591531 - 2³ = 71245591523 is a prime.

It is a super-2 number, since 2×71245591531² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71245591561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3210685 + ... + 3232798.

It is an arithmetic number, because the mean of its divisors is an integer number (17813011518).

Almost surely, 2^71245591531 is an apocalyptic number.

71245591531 is a deficient number, since it is larger than the sum of its proper divisors (6454541).

71245591531 is a wasteful number, since it uses less digits than its factorization.

71245591531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6454540.

The product of its digits is 189000, while the sum is 43.

The spelling of 71245591531 in words is "seventy-one billion, two hundred forty-five million, five hundred ninety-one thousand, five hundred thirty-one".