216031421 has 4 divisors (see below), whose sum is σ = 216293472. Its totient is φ = 215769372.

The previous prime is 216031399. The next prime is 216031429. The reversal of 216031421 is 124130612.

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 216031421 - 2⁶ = 216031357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216031393 and 216031402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216031429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129785 + ... + 131438.

It is an arithmetic number, because the mean of its divisors is an integer number (54073368).

Almost surely, 2^216031421 is an apocalyptic number.

It is an amenable number.

216031421 is a deficient number, since it is larger than the sum of its proper divisors (262051).

216031421 is an equidigital number, since it uses as much as digits as its factorization.

216031421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262050.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 216031421 is about 14698.0073819549. The cubic root of 216031421 is about 600.0290921079.

The spelling of 216031421 in words is "two hundred sixteen million, thirty-one thousand, four hundred twenty-one".