71257497481 has 27 divisors (see below), whose sum is σ = 75264545223. Its totient is φ = 67461329520.

The previous prime is 71257497469. The next prime is 71257497539. The reversal of 71257497481 is 18479475217.

The square root of 71257497481 is 266941.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 49666133881 + 21591363600 = 222859^2 + 146940^2 .

It is not a de Polignac number, because 71257497481 - 2²³ = 71249108873 is a prime.

It is a super-2 number, since 2×71257497481² (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 (71257497401) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 653738455 + ... + 653738563.

It is an arithmetic number, because the mean of its divisors is an integer number (2787575749).

Almost surely, 2^71257497481 is an apocalyptic number.

71257497481 is the 266941-st square number.

71257497481 is the 133471-st centered octagonal number.

It is an amenable number.

71257497481 is a deficient number, since it is larger than the sum of its proper divisors (4007047742).

71257497481 is an frugal number, since it uses more digits than its factorization.

71257497481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 219 counting only the distinct ones).

The product of its digits is 3951360, while the sum is 55.

The spelling of 71257497481 in words is "seventy-one billion, two hundred fifty-seven million, four hundred ninety-seven thousand, four hundred eighty-one".