21420101 has 8 divisors (see below), whose sum is σ = 22443264. Its totient is φ = 20417760.

The previous prime is 21420097. The next prime is 21420103. The reversal of 21420101 is 10102412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21420101 - 2² = 21420097 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 (21420103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3080 + ... + 7233.

It is an arithmetic number, because the mean of its divisors is an integer number (2805408).

Almost surely, 2^21420101 is an apocalyptic number.

It is an amenable number.

21420101 is a deficient number, since it is larger than the sum of its proper divisors (1023163).

21420101 is a wasteful number, since it uses less digits than its factorization.

21420101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10411.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21420101 is about 4628.1854975789. The cubic root of 21420101 is about 277.7200094922.

Adding to 21420101 its reverse (10102412), we get a palindrome (31522513).

The spelling of 21420101 in words is "twenty-one million, four hundred twenty thousand, one hundred one".