21934708447 has 4 divisors (see below), whose sum is σ = 21937569616. Its totient is φ = 21931847280.

The previous prime is 21934708373. The next prime is 21934708451. The reversal of 21934708447 is 74480743912.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21934708447 is a prime.

It is a super-2 number, since 2×21934708447² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21934708447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934708487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1419054 + ... + 1434427.

It is an arithmetic number, because the mean of its divisors is an integer number (5484392404).

Almost surely, 2^21934708447 is an apocalyptic number.

21934708447 is a deficient number, since it is larger than the sum of its proper divisors (2861169).

21934708447 is an equidigital number, since it uses as much as digits as its factorization.

21934708447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2861168.

The product of its (nonzero) digits is 1354752, while the sum is 49.

The spelling of 21934708447 in words is "twenty-one billion, nine hundred thirty-four million, seven hundred eight thousand, four hundred forty-seven".