71507943721 has 4 divisors (see below), whose sum is σ = 71771810944. Its totient is φ = 71244076500.

The previous prime is 71507943707. The next prime is 71507943733. The reversal of 71507943721 is 12734970517.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71507943721 - 2¹⁹ = 71507419433 is a prime.

It is a super-2 number, since 2×71507943721² (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 (71507943751) 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, 131933205 + ... + 131933746.

It is an arithmetic number, because the mean of its divisors is an integer number (17942952736).

Almost surely, 2^71507943721 is an apocalyptic number.

It is an amenable number.

71507943721 is a deficient number, since it is larger than the sum of its proper divisors (263867223).

71507943721 is a wasteful number, since it uses less digits than its factorization.

71507943721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263867222.

The product of its (nonzero) digits is 370440, while the sum is 46.

Subtracting from 71507943721 its product of nonzero digits (370440), we obtain a square (71507573281 = 267409²).

The spelling of 71507943721 in words is "seventy-one billion, five hundred seven million, nine hundred forty-three thousand, seven hundred twenty-one".