4000001521 has 2 divisors, whose sum is σ = 4000001522. Its totient is φ = 4000001520.

The previous prime is 4000001501. The next prime is 4000001567. The reversal of 4000001521 is 1251000004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3999297600 + 703921 = 63240^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 4000001521 - 2¹¹ = 3999999473 is a prime.

It is not a weakly prime, because it can be changed into another prime (4000001501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2000000760 + 2000000761.

It is an arithmetic number, because the mean of its divisors is an integer number (2000000761).

Almost surely, 2^4000001521 is an apocalyptic number.

It is an amenable number.

4000001521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4000001521 is an equidigital number, since it uses as much as digits as its factorization.

4000001521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 4000001521 is about 63245.5652279272. The cubic root of 4000001521 is about 1587.4012531713.

Adding to 4000001521 its reverse (1251000004), we get a palindrome (5251001525).

The spelling of 4000001521 in words is "four billion, one thousand, five hundred twenty-one".