21010541999 has 2 divisors, whose sum is σ = 21010542000. Its totient is φ = 21010541998.

The previous prime is 21010541977. The next prime is 21010542031. The reversal of 21010541999 is 99914501012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21010541999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010541899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505270999 + 10505271000.

It is an arithmetic number, because the mean of its divisors is an integer number (10505271000).

Almost surely, 2^21010541999 is an apocalyptic number.

21010541999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010541999 is an equidigital number, since it uses as much as digits as its factorization.

21010541999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 41.

The spelling of 21010541999 in words is "twenty-one billion, ten million, five hundred forty-one thousand, nine hundred ninety-nine".