21646722043 has 8 divisors (see below), whose sum is σ = 21908082240. Its totient is φ = 21386818440.

The previous prime is 21646722011. The next prime is 21646722049. The reversal of 21646722043 is 34022764612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21646722043 - 2⁵ = 21646722011 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21646721993 and 21646722011.

It is not an unprimeable number, because it can be changed into a prime (21646722049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 334233 + ... + 393706.

It is an arithmetic number, because the mean of its divisors is an integer number (2738510280).

Almost surely, 2^21646722043 is an apocalyptic number.

21646722043 is a deficient number, since it is larger than the sum of its proper divisors (261360197).

21646722043 is a wasteful number, since it uses less digits than its factorization.

21646722043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 728297.

The product of its (nonzero) digits is 96768, while the sum is 37.

The spelling of 21646722043 in words is "twenty-one billion, six hundred forty-six million, seven hundred twenty-two thousand, forty-three".