4200021521 has 2 divisors, whose sum is σ = 4200021522. Its totient is φ = 4200021520.

The previous prime is 4200021457. The next prime is 4200021557. The reversal of 4200021521 is 1251200024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2267188225 + 1932833296 = 47615^2 + 43964^2 .

It is a cyclic number.

It is not a de Polignac number, because 4200021521 - 2⁶ = 4200021457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 4200021521.

It is not a weakly prime, because it can be changed into another prime (4200021121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2100010760 + 2100010761.

It is an arithmetic number, because the mean of its divisors is an integer number (2100010761).

Almost surely, 2^4200021521 is an apocalyptic number.

It is an amenable number.

4200021521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4200021521 is an equidigital number, since it uses as much as digits as its factorization.

4200021521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 4200021521 is about 64807.5730219856. The cubic root of 4200021521 is about 1613.4314017816.

Adding to 4200021521 its reverse (1251200024), we get a palindrome (5451221545).

The spelling of 4200021521 in words is "four billion, two hundred million, twenty-one thousand, five hundred twenty-one".