21420141 has 4 divisors (see below), whose sum is σ = 28560192. Its totient is φ = 14280092.

The previous prime is 21420137. The next prime is 21420143. The reversal of 21420141 is 14102412.

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 21420141 - 2² = 21420137 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21420141.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420143) 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, 3570021 + ... + 3570026.

It is an arithmetic number, because the mean of its divisors is an integer number (7140048).

Almost surely, 2^21420141 is an apocalyptic number.

It is an amenable number.

21420141 is a deficient number, since it is larger than the sum of its proper divisors (7140051).

21420141 is an equidigital number, since it uses as much as digits as its factorization.

21420141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7140050.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 21420141 is about 4628.1898189249. The cubic root of 21420141 is about 277.7201823640.

Adding to 21420141 its reverse (14102412), we get a palindrome (35522553).

The spelling of 21420141 in words is "twenty-one million, four hundred twenty thousand, one hundred forty-one".