21980435855 has 32 divisors (see below), whose sum is σ = 33597711360. Its totient is φ = 13439070720.

The previous prime is 21980435843. The next prime is 21980435857. The reversal of 21980435855 is 55853408912.

It is not a de Polignac number, because 21980435855 - 2⁴ = 21980435839 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980435857) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 960851 + ... + 983460.

It is an arithmetic number, because the mean of its divisors is an integer number (1049928480).

Almost surely, 2^21980435855 is an apocalyptic number.

21980435855 is a deficient number, since it is larger than the sum of its proper divisors (11617275505).

21980435855 is a wasteful number, since it uses less digits than its factorization.

21980435855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1944359.

The product of its (nonzero) digits is 1728000, while the sum is 50.

The spelling of 21980435855 in words is "twenty-one billion, nine hundred eighty million, four hundred thirty-five thousand, eight hundred fifty-five".