21146229791 has 2 divisors, whose sum is σ = 21146229792. Its totient is φ = 21146229790.

The previous prime is 21146229787. The next prime is 21146229809. The reversal of 21146229791 is 19792264112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21146229791 - 2² = 21146229787 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21146225791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10573114895 + 10573114896.

It is an arithmetic number, because the mean of its divisors is an integer number (10573114896).

Almost surely, 2^21146229791 is an apocalyptic number.

21146229791 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146229791 is an equidigital number, since it uses as much as digits as its factorization.

21146229791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The spelling of 21146229791 in words is "twenty-one billion, one hundred forty-six million, two hundred twenty-nine thousand, seven hundred ninety-one".