7402821 has 4 divisors (see below), whose sum is σ = 9870432. Its totient is φ = 4935212.

The previous prime is 7402783. The next prime is 7402841. The reversal of 7402821 is 1282047.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7402821 - 2⁷ = 7402693 is a prime.

It is a Curzon number.

7402821 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7402791 and 7402800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7402841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1233801 + ... + 1233806.

It is an arithmetic number, because the mean of its divisors is an integer number (2467608).

Almost surely, 2^7402821 is an apocalyptic number.

It is an amenable number.

7402821 is a deficient number, since it is larger than the sum of its proper divisors (2467611).

7402821 is a wasteful number, since it uses less digits than its factorization.

7402821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2467610.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 7402821 is about 2720.8125624526. The cubic root of 7402821 is about 194.8942753647.

Adding to 7402821 its reverse (1282047), we get a palindrome (8684868).

The spelling of 7402821 in words is "seven million, four hundred two thousand, eight hundred twenty-one".