4121521021 has 16 divisors (see below), whose sum is σ = 4741839360. Its totient is φ = 3556362240.

The previous prime is 4121521009. The next prime is 4121521073. The reversal of 4121521021 is 1201251214.

It is a de Polignac number, because none of the positive numbers 2^k-4121521021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 4121521021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4121521081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 195796 + ... + 215821.

It is an arithmetic number, because the mean of its divisors is an integer number (296364960).

Almost surely, 2^4121521021 is an apocalyptic number.

It is an amenable number.

4121521021 is a deficient number, since it is larger than the sum of its proper divisors (620318339).

4121521021 is a wasteful number, since it uses less digits than its factorization.

4121521021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411684.

The product of its (nonzero) digits is 160, while the sum is 19.

The square root of 4121521021 is about 64199.0733655868. The cubic root of 4121521021 is about 1603.3161717391.

Adding to 4121521021 its reverse (1201251214), we get a palindrome (5322772235).

The spelling of 4121521021 in words is "four billion, one hundred twenty-one million, five hundred twenty-one thousand, twenty-one".