4002921 has 12 divisors (see below), whose sum is σ = 6226948. Its totient is φ = 2463264.

The previous prime is 4002917. The next prime is 4002923. The reversal of 4002921 is 1292004.

4002921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 2073600 + 1929321 = 1440^2 + 1389^2 .

It is not a de Polignac number, because 4002921 - 2² = 4002917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4002894 and 4002903.

It is not an unprimeable number, because it can be changed into a prime (4002923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16990 + ... + 17223.

Almost surely, 2^4002921 is an apocalyptic number.

It is an amenable number.

4002921 is a deficient number, since it is larger than the sum of its proper divisors (2224027).

4002921 is a wasteful number, since it uses less digits than its factorization.

4002921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34232 (or 34229 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 4002921 is about 2000.7301167324. The cubic root of 4002921 is about 158.7787357823.

Adding to 4002921 its reverse (1292004), we get a palindrome (5294925).

It can be divided in two parts, 400 and 2921, that added together give a triangular number (3321 = T₈₁).

The spelling of 4002921 in words is "four million, two thousand, nine hundred twenty-one".