21776434645 has 16 divisors (see below), whose sum is σ = 29869620480. Its totient is φ = 14930014464.

The previous prime is 21776434633. The next prime is 21776434703. The reversal of 21776434645 is 54643467712.

It is a cyclic number.

It is not a de Polignac number, because 21776434645 - 2⁵ = 21776434613 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 186936 + ... + 280174.

It is an arithmetic number, because the mean of its divisors is an integer number (1866851280).

Almost surely, 2^21776434645 is an apocalyptic number.

It is an amenable number.

21776434645 is a deficient number, since it is larger than the sum of its proper divisors (8093185835).

21776434645 is an equidigital number, since it uses as much as digits as its factorization.

21776434645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99924.

The product of its digits is 3386880, while the sum is 49.

The spelling of 21776434645 in words is "twenty-one billion, seven hundred seventy-six million, four hundred thirty-four thousand, six hundred forty-five".