21920382101 has 2 divisors, whose sum is σ = 21920382102. Its totient is φ = 21920382100.

The previous prime is 21920382079. The next prime is 21920382119. The reversal of 21920382101 is 10128302912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19564735876 + 2355646225 = 139874^2 + 48535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21920382101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21920382151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10960191050 + 10960191051.

It is an arithmetic number, because the mean of its divisors is an integer number (10960191051).

Almost surely, 2^21920382101 is an apocalyptic number.

It is an amenable number.

21920382101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21920382101 is an equidigital number, since it uses as much as digits as its factorization.

21920382101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The spelling of 21920382101 in words is "twenty-one billion, nine hundred twenty million, three hundred eighty-two thousand, one hundred one".