20143621 has 2 divisors, whose sum is σ = 20143622. Its totient is φ = 20143620.

The previous prime is 20143619. The next prime is 20143631. The reversal of 20143621 is 12634102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10962721 + 9180900 = 3311^2 + 3030^2 .

It is a cyclic number.

It is not a de Polignac number, because 20143621 - 2¹ = 20143619 is a prime.

Together with 20143619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20143631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10071810 + 10071811.

It is an arithmetic number, because the mean of its divisors is an integer number (10071811).

Almost surely, 2^20143621 is an apocalyptic number.

It is an amenable number.

20143621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20143621 is an equidigital number, since it uses as much as digits as its factorization.

20143621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 20143621 is about 4488.1645468944. The cubic root of 20143621 is about 272.0899581703.

Adding to 20143621 its reverse (12634102), we get a palindrome (32777723).

It can be divided in two parts, 20 and 143621, that added together give a square (143641 = 379²).

The spelling of 20143621 in words is "twenty million, one hundred forty-three thousand, six hundred twenty-one".