20278143 has 6 divisors (see below), whose sum is σ = 29290664. Its totient is φ = 13518756.

The previous prime is 20278129. The next prime is 20278147. The reversal of 20278143 is 34187202.

It is not a de Polignac number, because 20278143 - 2⁶ = 20278079 is a prime.

It is a super-2 number, since 2×20278143² = 822406167056898, which 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 (20278147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1126555 + ... + 1126572.

Almost surely, 2^20278143 is an apocalyptic number.

20278143 is a deficient number, since it is larger than the sum of its proper divisors (9012521).

20278143 is a wasteful number, since it uses less digits than its factorization.

20278143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2253133 (or 2253130 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 20278143 is about 4503.1259142955. The cubic root of 20278143 is about 272.6943001653.

The spelling of 20278143 in words is "twenty million, two hundred seventy-eight thousand, one hundred forty-three".