78203710812545 has 4 divisors (see below), whose sum is σ = 93844452975060. Its totient is φ = 62562968650032.

The previous prime is 78203710812529. The next prime is 78203710812559. The reversal of 78203710812545 is 54521801730287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39378549204289 + 38825161608256 = 6275233^2 + 6230984^2 .

It is a cyclic number.

It is not a de Polignac number, because 78203710812545 - 2⁴ = 78203710812529 is a prime.

It is a super-2 number, since 2×78203710812545² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7820371081250 + ... + 7820371081259.

It is an arithmetic number, because the mean of its divisors is an integer number (23461113243765).

Almost surely, 2^{78203710812545} is an apocalyptic number.

It is an amenable number.

78203710812545 is a deficient number, since it is larger than the sum of its proper divisors (15640742162515).

78203710812545 is a wasteful number, since it uses less digits than its factorization.

78203710812545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15640742162514.

The product of its (nonzero) digits is 3763200, while the sum is 53.

The spelling of 78203710812545 in words is "seventy-eight trillion, two hundred three billion, seven hundred ten million, eight hundred twelve thousand, five hundred forty-five".