78420197 has 8 divisors (see below), whose sum is σ = 79916760. Its totient is φ = 76930560.

The previous prime is 78420187. The next prime is 78420203. The reversal of 78420197 is 79102487.

It can be written as a sum of positive squares in 4 ways, for example, as 17048641 + 61371556 = 4129^2 + 7834^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 78420197 - 2²⁰ = 77371621 is a prime.

It is a super-2 number, since 2×78420197² = 12299454595037618, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78420197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78420157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24929 + ... + 27897.

It is an arithmetic number, because the mean of its divisors is an integer number (9989595).

Almost surely, 2^78420197 is an apocalyptic number.

It is an amenable number.

78420197 is a deficient number, since it is larger than the sum of its proper divisors (1496563).

78420197 is a wasteful number, since it uses less digits than its factorization.

78420197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3463.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 78420197 is about 8855.5178843476. The cubic root of 78420197 is about 428.0317416847.

The spelling of 78420197 in words is "seventy-eight million, four hundred twenty thousand, one hundred ninety-seven".