78215020277 has 2 divisors, whose sum is σ = 78215020278. Its totient is φ = 78215020276.

The previous prime is 78215020259. The next prime is 78215020307. The reversal of 78215020277 is 77202051287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76168272196 + 2046748081 = 275986^2 + 45241^2 .

It is an emirp because it is prime and its reverse (77202051287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78215020277 - 2¹⁸ = 78214758133 is a prime.

It is a super-2 number, since 2×78215020277² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78215020207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39107510138 + 39107510139.

It is an arithmetic number, because the mean of its divisors is an integer number (39107510139).

Almost surely, 2^78215020277 is an apocalyptic number.

It is an amenable number.

78215020277 is a deficient number, since it is larger than the sum of its proper divisors (1).

78215020277 is an equidigital number, since it uses as much as digits as its factorization.

78215020277 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 109760, while the sum is 41.

The spelling of 78215020277 in words is "seventy-eight billion, two hundred fifteen million, twenty thousand, two hundred seventy-seven".