71944029649 has 4 divisors (see below), whose sum is σ = 72316796836. Its totient is φ = 71571262464.

The previous prime is 71944029637. The next prime is 71944029709. The reversal of 71944029649 is 94692044917.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94692044917 = 4021 ⋅23549377.

It can be written as a sum of positive squares in 2 ways, for example, as 5635204624 + 66308825025 = 75068^2 + 257505^2 .

It is a cyclic number.

It is not a de Polignac number, because 71944029649 - 2⁵ = 71944029617 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71944029649.

It is not an unprimeable number, because it can be changed into a prime (71944029749) 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, 186383304 + ... + 186383689.

It is an arithmetic number, because the mean of its divisors is an integer number (18079199209).

Almost surely, 2^71944029649 is an apocalyptic number.

It is an amenable number.

71944029649 is a deficient number, since it is larger than the sum of its proper divisors (372767187).

71944029649 is a wasteful number, since it uses less digits than its factorization.

71944029649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372767186.

The product of its (nonzero) digits is 3919104, while the sum is 55.

The spelling of 71944029649 in words is "seventy-one billion, nine hundred forty-four million, twenty-nine thousand, six hundred forty-nine".