21128380558 has 16 divisors (see below), whose sum is σ = 31784309424. Its totient is φ = 10533654720.

The previous prime is 21128380549. The next prime is 21128380561. The reversal of 21128380558 is 85508382112.

It is a super-3 number, since 3×21128380558³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1019338 + ... + 1039858.

It is an arithmetic number, because the mean of its divisors is an integer number (1986519339).

Almost surely, 2^21128380558 is an apocalyptic number.

21128380558 is a deficient number, since it is larger than the sum of its proper divisors (10655928866).

21128380558 is a wasteful number, since it uses less digits than its factorization.

21128380558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21987.

The product of its (nonzero) digits is 153600, while the sum is 43.

The spelling of 21128380558 in words is "twenty-one billion, one hundred twenty-eight million, three hundred eighty thousand, five hundred fifty-eight".