1011201021 has 24 divisors (see below), whose sum is σ = 1548840384. Its totient is φ = 633536640.

The previous prime is 1011201019. The next prime is 1011201077. The reversal of 1011201021 is 1201021101.

It is a happy number.

It is not a de Polignac number, because 1011201021 - 2¹ = 1011201019 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 = 1011200994 and 1011201012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011201011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106686 + ... + 115776.

It is an arithmetic number, because the mean of its divisors is an integer number (64535016).

Almost surely, 2^1011201021 is an apocalyptic number.

It is an amenable number.

1011201021 is a deficient number, since it is larger than the sum of its proper divisors (537639363).

1011201021 is a wasteful number, since it uses less digits than its factorization.

1011201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9841 (or 9838 counting only the distinct ones).

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

The square root of 1011201021 is about 31799.3871167354. The cubic root of 1011201021 is about 1003.7198194528.

Adding to 1011201021 its reverse (1201021101), we get a palindrome (2212222122).

It can be divided in two parts, 101 and 1201021, that multiplied together give a palindrome (121303121).

The spelling of 1011201021 in words is "one billion, eleven million, two hundred one thousand, twenty-one".