4000521 has 16 divisors (see below), whose sum is σ = 6307200. Its totient is φ = 2206848.

The previous prime is 4000511. The next prime is 4000523. The reversal of 4000521 is 1250004.

It is not a de Polignac number, because 4000521 - 2⁵ = 4000489 is a prime.

4000521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4000497 and 4000506.

It is not an unprimeable number, because it can be changed into a prime (4000523) 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, 2676 + ... + 3893.

It is an arithmetic number, because the mean of its divisors is an integer number (394200).

Almost surely, 2^4000521 is an apocalyptic number.

It is an amenable number.

4000521 is a deficient number, since it is larger than the sum of its proper divisors (2306679).

4000521 is a wasteful number, since it uses less digits than its factorization.

4000521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6608.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 4000521 is about 2000.1302457590. The cubic root of 4000521 is about 158.7469968638.

Adding to 4000521 its reverse (1250004), we get a palindrome (5250525).

The spelling of 4000521 in words is "four million, five hundred twenty-one", and thus it is an aban number.