1021110021 has 12 divisors (see below), whose sum is σ = 1475461260. Its totient is φ = 680497920.

The previous prime is 1021110017. The next prime is 1021110029. The reversal of 1021110021 is 1200111201.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 810540900 + 210569121 = 28470^2 + 14511^2 .

It is not a de Polignac number, because 1021110021 - 2² = 1021110017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1021109985 and 1021110012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021110029) 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 11 ways as a sum of consecutive naturals, for example, 8715 + ... + 46023.

It is an arithmetic number, because the mean of its divisors is an integer number (122955105).

Almost surely, 2^1021110021 is an apocalyptic number.

It is an amenable number.

1021110021 is a deficient number, since it is larger than the sum of its proper divisors (454351239).

1021110021 is a wasteful number, since it uses less digits than its factorization.

1021110021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40356 (or 40353 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1021110021 is about 31954.8121728168. The cubic root of 1021110021 is about 1006.9877315413.

Adding to 1021110021 its reverse (1200111201), we get a palindrome (2221221222).

The spelling of 1021110021 in words is "one billion, twenty-one million, one hundred ten thousand, twenty-one".