20078197 has 4 divisors (see below), whose sum is σ = 20213100. Its totient is φ = 19943296.

The previous prime is 20078189. The next prime is 20078213. The reversal of 20078197 is 79187002.

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 13060996 + 7017201 = 3614^2 + 2649^2 .

It is a cyclic number.

It is not a de Polignac number, because 20078197 - 2³ = 20078189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20078137) 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, 67228 + ... + 67525.

It is an arithmetic number, because the mean of its divisors is an integer number (5053275).

Almost surely, 2^20078197 is an apocalyptic number.

It is an amenable number.

20078197 is a deficient number, since it is larger than the sum of its proper divisors (134903).

20078197 is a wasteful number, since it uses less digits than its factorization.

20078197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134902.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20078197 is about 4480.8701163948. The cubic root of 20078197 is about 271.7950671256.

The spelling of 20078197 in words is "twenty million, seventy-eight thousand, one hundred ninety-seven".