7402421 has 4 divisors (see below), whose sum is σ = 7971852. Its totient is φ = 6832992.

The previous prime is 7402403. The next prime is 7402433. The reversal of 7402421 is 1242047.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1242047 = 479 ⋅2593.

It can be written as a sum of positive squares in 2 ways, for example, as 1575025 + 5827396 = 1255^2 + 2414^2 .

It is a cyclic number.

It is not a de Polignac number, because 7402421 - 2¹⁸ = 7140277 is a prime.

It is a super-2 number, since 2×7402421² = 109591673322482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 7402393 and 7402402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7402441) 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, 284696 + ... + 284721.

It is an arithmetic number, because the mean of its divisors is an integer number (1992963).

Almost surely, 2^7402421 is an apocalyptic number.

It is an amenable number.

7402421 is a deficient number, since it is larger than the sum of its proper divisors (569431).

7402421 is a wasteful number, since it uses less digits than its factorization.

7402421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569430.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 7402421 is about 2720.7390540072. The cubic root of 7402421 is about 194.8907650311.

Adding to 7402421 its reverse (1242047), we get a palindrome (8644468).

The spelling of 7402421 in words is "seven million, four hundred two thousand, four hundred twenty-one".