21224400101 has 2 divisors, whose sum is σ = 21224400102. Its totient is φ = 21224400100.

The previous prime is 21224400089. The next prime is 21224400137. The reversal of 21224400101 is 10100442212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20241891076 + 982509025 = 142274^2 + 31345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21224400101 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21224400101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21224405101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612200050 + 10612200051.

It is an arithmetic number, because the mean of its divisors is an integer number (10612200051).

Almost surely, 2^21224400101 is an apocalyptic number.

It is an amenable number.

21224400101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21224400101 is an equidigital number, since it uses as much as digits as its factorization.

21224400101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21224400101 its reverse (10100442212), we get a palindrome (31324842313).

The spelling of 21224400101 in words is "twenty-one billion, two hundred twenty-four million, four hundred thousand, one hundred one".