78242574475421 has 4 divisors (see below), whose sum is σ = 78244081249500. Its totient is φ = 78241067701344.

The previous prime is 78242574475409. The next prime is 78242574475477. The reversal of 78242574475421 is 12457447524287.

It is a happy number.

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 49949004986521 + 28293569488900 = 7067461^2 + 5319170^2 .

It is a cyclic number.

It is not a de Polignac number, because 78242574475421 - 2¹⁸ = 78242574213277 is a prime.

It is a super-2 number, since 2×78242574475421² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78242574475321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 753309146 + ... + 753413003.

It is an arithmetic number, because the mean of its divisors is an integer number (19561020312375).

Almost surely, 2^{78242574475421} is an apocalyptic number.

It is an amenable number.

78242574475421 is a deficient number, since it is larger than the sum of its proper divisors (1506774079).

78242574475421 is a wasteful number, since it uses less digits than its factorization.

78242574475421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506774078.

The product of its digits is 140492800, while the sum is 62.

The spelling of 78242574475421 in words is "seventy-eight trillion, two hundred forty-two billion, five hundred seventy-four million, four hundred seventy-five thousand, four hundred twenty-one".