21145109564101 has 2 divisors, whose sum is σ = 21145109564102. Its totient is φ = 21145109564100.

The previous prime is 21145109564083. The next prime is 21145109564113. The reversal of 21145109564101 is 10146590154112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20363784390625 + 781325173476 = 4512625^2 + 883926^2 .

It is a cyclic number.

It is not a de Polignac number, because 21145109564101 - 2³³ = 21136519629509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145109564401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572554782050 + 10572554782051.

It is an arithmetic number, because the mean of its divisors is an integer number (10572554782051).

Almost surely, 2^{21145109564101} is an apocalyptic number.

It is an amenable number.

21145109564101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145109564101 is an equidigital number, since it uses as much as digits as its factorization.

21145109564101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43200, while the sum is 40.

The spelling of 21145109564101 in words is "twenty-one trillion, one hundred forty-five billion, one hundred nine million, five hundred sixty-four thousand, one hundred one".