78072050833921 has 9 divisors (see below), whose sum is σ = 78139960231683. Its totient is φ = 78004200426240.

The previous prime is 78072050833919. The next prime is 78072050833937. The reversal of 78072050833921 is 12933805027087.

The square root of 78072050833921 is 8835839.

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., 994186473921 + 77077864360000 = 997089^2 + 8779400^2 .

It is not a de Polignac number, because 78072050833921 - 2¹ = 78072050833919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78072050833121) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12449694016 + ... + 12449700286.

Almost surely, 2^{78072050833921} is an apocalyptic number.

78072050833921 is the 8835839-th square number.

78072050833921 is the 4417920-th centered octagonal number.

It is an amenable number.

78072050833921 is a deficient number, since it is larger than the sum of its proper divisors (67909397762).

78072050833921 is an frugal number, since it uses more digits than its factorization.

78072050833921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15360 (or 7680 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 78072050833921 in words is "seventy-eight trillion, seventy-two billion, fifty million, eight hundred thirty-three thousand, nine hundred twenty-one".