20278631 has 2 divisors, whose sum is σ = 20278632. Its totient is φ = 20278630.

The previous prime is 20278613. The next prime is 20278649. The reversal of 20278631 is 13687202.

It is a happy number.

Together with previous prime (20278613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a balanced prime because it is at equal distance from previous prime (20278613) and next prime (20278649).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20278631 is a prime.

It is a super-2 number, since 2×20278631² = 822445750468322, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20278594 and 20278603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20278651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10139315 + 10139316.

It is an arithmetic number, because the mean of its divisors is an integer number (10139316).

Almost surely, 2^20278631 is an apocalyptic number.

20278631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20278631 is an equidigital number, since it uses as much as digits as its factorization.

20278631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 20278631 is about 4503.1800985526. The cubic root of 20278631 is about 272.6964876396.

The spelling of 20278631 in words is "twenty million, two hundred seventy-eight thousand, six hundred thirty-one".