4015021 has 4 divisors (see below), whose sum is σ = 4153500. Its totient is φ = 3876544.

The previous prime is 4015013. The next prime is 4015031. The reversal of 4015021 is 1205104.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2992900 + 1022121 = 1730^2 + 1011^2 .

It is a cyclic number.

It is not a de Polignac number, because 4015021 - 2³ = 4015013 is a prime.

It is a super-2 number, since 2×4015021² = 32240787260882, which contains 22 as substring.

It is a Duffinian number.

4015021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4014992 and 4015010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4015031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69196 + ... + 69253.

It is an arithmetic number, because the mean of its divisors is an integer number (1038375).

Almost surely, 2^4015021 is an apocalyptic number.

It is an amenable number.

4015021 is a deficient number, since it is larger than the sum of its proper divisors (138479).

4015021 is a wasteful number, since it uses less digits than its factorization.

4015021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138478.

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

The square root of 4015021 is about 2003.7517311284. The cubic root of 4015021 is about 158.9385599147.

The spelling of 4015021 in words is "four million, fifteen thousand, twenty-one".