21953697011 has 2 divisors, whose sum is σ = 21953697012. Its totient is φ = 21953697010.

The previous prime is 21953697001. The next prime is 21953697049. The reversal of 21953697011 is 11079635912.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21953697011 is a prime.

It is not a weakly prime, because it can be changed into another prime (21953697001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10976848505 + 10976848506.

It is an arithmetic number, because the mean of its divisors is an integer number (10976848506).

Almost surely, 2^21953697011 is an apocalyptic number.

21953697011 is a deficient number, since it is larger than the sum of its proper divisors (1).

21953697011 is an equidigital number, since it uses as much as digits as its factorization.

21953697011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 102060, while the sum is 44.

The spelling of 21953697011 in words is "twenty-one billion, nine hundred fifty-three million, six hundred ninety-seven thousand, eleven".