431240021 has 4 divisors (see below), whose sum is σ = 431358444. Its totient is φ = 431121600.

The previous prime is 431240011. The next prime is 431240023. The reversal of 431240021 is 120042134.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 182547121 + 248692900 = 13511^2 + 15770^2 .

It is a cyclic number.

It is not a de Polignac number, because 431240021 - 2⁶ = 431239957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (431240023) 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, 53570 + ... + 61091.

It is an arithmetic number, because the mean of its divisors is an integer number (107839611).

Almost surely, 2^431240021 is an apocalyptic number.

It is an amenable number.

431240021 is a deficient number, since it is larger than the sum of its proper divisors (118423).

431240021 is a wasteful number, since it uses less digits than its factorization.

431240021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118422.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 431240021 is about 20766.3193898197. The cubic root of 431240021 is about 755.5090764284.

Adding to 431240021 its reverse (120042134), we get a palindrome (551282155).

The spelling of 431240021 in words is "four hundred thirty-one million, two hundred forty thousand, twenty-one".