20210101 has 2 divisors, whose sum is σ = 20210102.
Its totient is φ = 20210100.
The previous prime is 20210087. The next prime is 20210107. The reversal of 20210101 is 10101202.
Adding to 20210101 its reverse (10101202), we get a palindrome (30311303).
It can be divided in two parts, 20210 and 101, that multiplied together give a triangular number (2041210 = T2020).
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 17023876 + 3186225 = 4126^2 + 1785^2
It is a cyclic number.
It is not a de Polignac number, because 20210101 - 221 = 18112949 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20210107) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105050 + 10105051.
It is an arithmetic number, because the mean of its divisors is an integer number (10105051).
Almost surely, 220210101 is an apocalyptic number.
It is an amenable number.
20210101 is a deficient number, since it is larger than the sum of its proper divisors (1).
20210101 is an equidigital number, since it uses as much as digits as its factorization.
20210101 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 4, while the sum is 7.
The square root of 20210101 is about 4495.5645919061.
The cubic root of 20210101 is about 272.3889556812.
The spelling of 20210101 in words is "twenty million, two hundred ten thousand, one hundred one".