1211020101 has 24 divisors (see below), whose sum is σ = 1802119904. Its totient is φ = 783082080.

The previous prime is 1211020087. The next prime is 1211020103. The reversal of 1211020101 is 1010201121.

It is a happy number.

It is not a de Polignac number, because 1211020101 - 2⁶ = 1211020037 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 (1211020103) 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, 104730 + ... + 115716.

Almost surely, 2^1211020101 is an apocalyptic number.

It is an amenable number.

1211020101 is a deficient number, since it is larger than the sum of its proper divisors (591099803).

1211020101 is a wasteful number, since it uses less digits than its factorization.

1211020101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11361 (or 11358 counting only the distinct ones).

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

The square root of 1211020101 is about 34799.7140936531. The cubic root of 1211020101 is about 1065.9016077242.

Adding to 1211020101 its reverse (1010201121), we get a palindrome (2221221222).

It can be divided in two parts, 1211020 and 101, that added together give a palindrome (1211121).

The spelling of 1211020101 in words is "one billion, two hundred eleven million, twenty thousand, one hundred one".