1011021021 has 20 divisors (see below), whose sum is σ = 1512852352. Its totient is φ = 672870888.

The previous prime is 1011021013. The next prime is 1011021047. The reversal of 1011021021 is 1201201101.

It is a happy number.

It is not a de Polignac number, because 1011021021 - 2³ = 1011021013 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 junction number, because it is equal to n+sod(n) for n = 1011020994 and 1011021012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011021001) 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 19 ways as a sum of consecutive naturals, for example, 38886 + ... + 59448.

Almost surely, 2^1011021021 is an apocalyptic number.

It is an amenable number.

1011021021 is a deficient number, since it is larger than the sum of its proper divisors (501831331).

1011021021 is an equidigital number, since it uses as much as digits as its factorization.

1011021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21182 (or 21173 counting only the distinct ones).

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

The square root of 1011021021 is about 31796.5567475474. The cubic root of 1011021021 is about 1003.6602598186.

Adding to 1011021021 its reverse (1201201101), we get a palindrome (2212222122).

The spelling of 1011021021 in words is "one billion, eleven million, twenty-one thousand, twenty-one".