21923429447 has 2 divisors, whose sum is σ = 21923429448. Its totient is φ = 21923429446.

The previous prime is 21923429443. The next prime is 21923429491. The reversal of 21923429447 is 74492432912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21923429447 - 2² = 21923429443 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21923429441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10961714723 + 10961714724.

It is an arithmetic number, because the mean of its divisors is an integer number (10961714724).

Almost surely, 2^21923429447 is an apocalyptic number.

21923429447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21923429447 is an equidigital number, since it uses as much as digits as its factorization.

21923429447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 47.

The spelling of 21923429447 in words is "twenty-one billion, nine hundred twenty-three million, four hundred twenty-nine thousand, four hundred forty-seven".