1010101021 has 4 divisors (see below), whose sum is σ = 1010220444. Its totient is φ = 1009981600.

The previous prime is 1010101007. The next prime is 1010101039. The reversal of 1010101021 is 1201010101.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 445800996 + 564300025 = 21114^2 + 23755^2 .

It is a cyclic number.

It is not a de Polignac number, because 1010101021 - 2²⁷ = 875883293 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1010100995 and 1010101013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1010101091) 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 3 ways as a sum of consecutive naturals, for example, 45970 + ... + 64291.

It is an arithmetic number, because the mean of its divisors is an integer number (252555111).

Almost surely, 2^1010101021 is an apocalyptic number.

It is an amenable number.

1010101021 is a deficient number, since it is larger than the sum of its proper divisors (119423).

1010101021 is an equidigital number, since it uses as much as digits as its factorization.

1010101021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119422.

The product of its (nonzero) digits is 2, while the sum is 7.

The square root of 1010101021 is about 31782.0864796508. The cubic root of 1010101021 is about 1003.3557334567.

Adding to 1010101021 its reverse (1201010101), we get a palindrome (2211111122).

The spelling of 1010101021 in words is "one billion, ten million, one hundred one thousand, twenty-one".