21946069729 has 4 divisors (see below), whose sum is σ = 22223868160. Its totient is φ = 21668271300.

The previous prime is 21946069687. The next prime is 21946069741. The reversal of 21946069729 is 92796064912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21946069729 - 2¹⁵ = 21946036961 is a prime.

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 21946069729.

It is not an unprimeable number, because it can be changed into a prime (21946069759) 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, 138899097 + ... + 138899254.

It is an arithmetic number, because the mean of its divisors is an integer number (5555967040).

Almost surely, 2^21946069729 is an apocalyptic number.

It is an amenable number.

21946069729 is a deficient number, since it is larger than the sum of its proper divisors (277798431).

21946069729 is an equidigital number, since it uses as much as digits as its factorization.

21946069729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277798430.

The product of its (nonzero) digits is 2939328, while the sum is 55.

The spelling of 21946069729 in words is "twenty-one billion, nine hundred forty-six million, sixty-nine thousand, seven hundred twenty-nine".