71747781497 has 4 divisors (see below), whose sum is σ = 81997464576. Its totient is φ = 61498098420.

The previous prime is 71747781421. The next prime is 71747781583. The reversal of 71747781497 is 79418774717.

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 71747781497 - 2¹⁰ = 71747780473 is a prime.

It is a super-2 number, since 2×71747781497² (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 (71747781397) 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, 5124841529 + ... + 5124841542.

It is an arithmetic number, because the mean of its divisors is an integer number (20499366144).

Almost surely, 2^71747781497 is an apocalyptic number.

It is an amenable number.

71747781497 is a deficient number, since it is larger than the sum of its proper divisors (10249683079).

71747781497 is a wasteful number, since it uses less digits than its factorization.

71747781497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10249683078.

The product of its digits is 19361664, while the sum is 62.

The spelling of 71747781497 in words is "seventy-one billion, seven hundred forty-seven million, seven hundred eighty-one thousand, four hundred ninety-seven".