20278147 has 2 divisors, whose sum is σ = 20278148. Its totient is φ = 20278146.

The previous prime is 20278129. The next prime is 20278151. The reversal of 20278147 is 74187202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20278147 - 2²³ = 11889539 is a prime.

It is a super-2 number, since 2×20278147² = 822406491507218, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20278177) 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 as a sum of consecutive naturals, namely, 10139073 + 10139074.

It is an arithmetic number, because the mean of its divisors is an integer number (10139074).

Almost surely, 2^20278147 is an apocalyptic number.

20278147 is a deficient number, since it is larger than the sum of its proper divisors (1).

20278147 is an equidigital number, since it uses as much as digits as its factorization.

20278147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6272, while the sum is 31.

The square root of 20278147 is about 4503.1263584314. The cubic root of 20278147 is about 272.6943180956.

The spelling of 20278147 in words is "twenty million, two hundred seventy-eight thousand, one hundred forty-seven".