71507558138172 has 144 divisors (see below), whose sum is σ = 186752235091968. Its totient is φ = 21263901684480.

The previous prime is 71507558138143. The next prime is 71507558138209. The reversal of 71507558138172 is 27183185570517.

It is a super-2 number, since 2×71507558138172² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 45945498 + ... + 47476350.

It is an arithmetic number, because the mean of its divisors is an integer number (1296890521472).

Almost surely, 2^{71507558138172} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71507558138172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93376117545984).

71507558138172 is an abundant number, since it is smaller than the sum of its proper divisors (115244676953796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71507558138172 is a wasteful number, since it uses less digits than its factorization.

71507558138172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1531660 (or 1531645 counting only the distinct ones).

The product of its (nonzero) digits is 16464000, while the sum is 60.

The spelling of 71507558138172 in words is "seventy-one trillion, five hundred seven billion, five hundred fifty-eight million, one hundred thirty-eight thousand, one hundred seventy-two".