21213420101 has 4 divisors (see below), whose sum is σ = 21213725472. Its totient is φ = 21213114732.

The previous prime is 21213420091. The next prime is 21213420119. The reversal of 21213420101 is 10102431212.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21213420101 - 2⁶ = 21213420037 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21213420101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213420161) 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, 7616 + ... + 206118.

It is an arithmetic number, because the mean of its divisors is an integer number (5303431368).

Almost surely, 2^21213420101 is an apocalyptic number.

It is an amenable number.

21213420101 is a deficient number, since it is larger than the sum of its proper divisors (305371).

21213420101 is a wasteful number, since it uses less digits than its factorization.

21213420101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305370.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21213420101 its reverse (10102431212), we get a palindrome (31315851313).

The spelling of 21213420101 in words is "twenty-one billion, two hundred thirteen million, four hundred twenty thousand, one hundred one".