78145775244021 has 8 divisors (see below), whose sum is σ = 109678281044320. Its totient is φ = 49355226469872.

The previous prime is 78145775243993. The next prime is 78145775244049. The reversal of 78145775244021 is 12044257754187.

It is a happy number.

78145775244021 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (78145775243993) and next prime (78145775244049).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78145775244021 - 2¹⁸ = 78145774981877 is a prime.

It is a super-2 number, since 2×78145775244021² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 1370978513053 = 78145775244021 / (7 + 8 + 1 + 4 + 5 + 7 + 7 + 5 + 2 + 4 + 4 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78145775044021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 685489256470 + ... + 685489256583.

It is an arithmetic number, because the mean of its divisors is an integer number (13709785130540).

Almost surely, 2^{78145775244021} is an apocalyptic number.

It is an amenable number.

78145775244021 is a deficient number, since it is larger than the sum of its proper divisors (31532505800299).

78145775244021 is a wasteful number, since it uses less digits than its factorization.

78145775244021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1370978513075.

The product of its (nonzero) digits is 17561600, while the sum is 57.

The spelling of 78145775244021 in words is "seventy-eight trillion, one hundred forty-five billion, seven hundred seventy-five million, two hundred forty-four thousand, twenty-one".