20280101 has 2 divisors, whose sum is σ = 20280102. Its totient is φ = 20280100.

The previous prime is 20280067. The next prime is 20280103. The reversal of 20280101 is 10108202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20205025 + 75076 = 4495^2 + 274^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20280101 is a prime.

It is a super-2 number, since 2×20280101² = 822564993140402, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 20280103, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20280103) 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, 10140050 + 10140051.

It is an arithmetic number, because the mean of its divisors is an integer number (10140051).

Almost surely, 2^20280101 is an apocalyptic number.

It is an amenable number.

20280101 is a deficient number, since it is larger than the sum of its proper divisors (1).

20280101 is an equidigital number, since it uses as much as digits as its factorization.

20280101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 20280101 is about 4503.3433135838. The cubic root of 20280101 is about 272.7030767457.

Adding to 20280101 its reverse (10108202), we get a palindrome (30388303).

The spelling of 20280101 in words is "twenty million, two hundred eighty thousand, one hundred one".