4240021421 has 4 divisors (see below), whose sum is σ = 4240795200. Its totient is φ = 4239247644.

The previous prime is 4240021277. The next prime is 4240021441. The reversal of 4240021421 is 1241200424.

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 a de Polignac number, because none of the positive numbers 2^k-4240021421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 4240021393 and 4240021402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4240021441) 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, 378611 + ... + 389648.

It is an arithmetic number, because the mean of its divisors is an integer number (1060198800).

Almost surely, 2^4240021421 is an apocalyptic number.

It is an amenable number.

4240021421 is a deficient number, since it is larger than the sum of its proper divisors (773779).

4240021421 is an equidigital number, since it uses as much as digits as its factorization.

4240021421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773778.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 4240021421 is about 65115.4468693873. The cubic root of 4240021421 is about 1618.5371925869.

Adding to 4240021421 its reverse (1241200424), we get a palindrome (5481221845).

The spelling of 4240021421 in words is "four billion, two hundred forty million, twenty-one thousand, four hundred twenty-one".