424120021 has 16 divisors (see below), whose sum is σ = 472665088. Its totient is φ = 377913600.

The previous prime is 424119989. The next prime is 424120091. The reversal of 424120021 is 120021424.

It is a 10-Lehmer number, since φ(424120021) divides (424120021-1)¹⁰.

It is a cyclic number.

It is not a de Polignac number, because 424120021 - 2⁵ = 424119989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 424119977 and 424120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (424120091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 195181 + ... + 197341.

It is an arithmetic number, because the mean of its divisors is an integer number (29541568).

Almost surely, 2^424120021 is an apocalyptic number.

It is an amenable number.

424120021 is a deficient number, since it is larger than the sum of its proper divisors (48545067).

424120021 is a wasteful number, since it uses less digits than its factorization.

424120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2692.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 424120021 is about 20594.1744432740. The cubic root of 424120021 is about 751.3280298757.

Adding to 424120021 its reverse (120021424), we get a palindrome (544141445).

The spelling of 424120021 in words is "four hundred twenty-four million, one hundred twenty thousand, twenty-one".