78150015872521 has 2 divisors, whose sum is σ = 78150015872522. Its totient is φ = 78150015872520.

The previous prime is 78150015872477. The next prime is 78150015872563. The reversal of 78150015872521 is 12527851005187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65662838834121 + 12487177038400 = 8103261^2 + 3533720^2 .

It is a cyclic number.

It is not a de Polignac number, because 78150015872521 - 2¹¹ = 78150015870473 is a prime.

It is a super-2 number, since 2×78150015872521² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78150025872521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39075007936260 + 39075007936261.

It is an arithmetic number, because the mean of its divisors is an integer number (39075007936261).

Almost surely, 2^{78150015872521} is an apocalyptic number.

It is an amenable number.

78150015872521 is a deficient number, since it is larger than the sum of its proper divisors (1).

78150015872521 is an equidigital number, since it uses as much as digits as its factorization.

78150015872521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1568000, while the sum is 52.

The spelling of 78150015872521 in words is "seventy-eight trillion, one hundred fifty billion, fifteen million, eight hundred seventy-two thousand, five hundred twenty-one".