1021210101 has 24 divisors (see below), whose sum is σ = 1516745984. Its totient is φ = 661620960.

The previous prime is 1021210079. The next prime is 1021210103. The reversal of 1021210101 is 1010121201.

It is a happy number.

It is not a de Polignac number, because 1021210101 - 2⁶ = 1021210037 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021210103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 440736 + ... + 443046.

Almost surely, 2^1021210101 is an apocalyptic number.

It is an amenable number.

1021210101 is a deficient number, since it is larger than the sum of its proper divisors (495535883).

1021210101 is a wasteful number, since it uses less digits than its factorization.

1021210101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3681 (or 3678 counting only the distinct ones).

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

The square root of 1021210101 is about 31956.3780957730. The cubic root of 1021210101 is about 1007.0206290868.

Adding to 1021210101 its reverse (1010121201), we get a palindrome (2031331302).

Subtracting from 1021210101 its reverse (1010121201), we obtain a square (11088900 = 3330²).

The spelling of 1021210101 in words is "one billion, twenty-one million, two hundred ten thousand, one hundred one".