71642133721 has 4 divisors (see below), whose sum is σ = 71647744000. Its totient is φ = 71636523444.

The previous prime is 71642133709. The next prime is 71642133817. The reversal of 71642133721 is 12733124617.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12733124617 = 6323 ⋅2013779.

It is a cyclic number.

It is not a de Polignac number, because 71642133721 - 2⁷ = 71642133593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71642133821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2785941 + ... + 2811538.

It is an arithmetic number, because the mean of its divisors is an integer number (17911936000).

Almost surely, 2^71642133721 is an apocalyptic number.

It is an amenable number.

71642133721 is a deficient number, since it is larger than the sum of its proper divisors (5610279).

71642133721 is a wasteful number, since it uses less digits than its factorization.

71642133721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5610278.

The product of its digits is 42336, while the sum is 37.

The spelling of 71642133721 in words is "seventy-one billion, six hundred forty-two million, one hundred thirty-three thousand, seven hundred twenty-one".