21028973558 has 32 divisors (see below), whose sum is σ = 34007869440. Its totient is φ = 9721801440.

The previous prime is 21028973557. The next prime is 21028973561. The reversal of 21028973558 is 85537982012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21028973557) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 357341 + ... + 412007.

It is an arithmetic number, because the mean of its divisors is an integer number (1062745920).

Almost surely, 2^21028973558 is an apocalyptic number.

21028973558 is a deficient number, since it is larger than the sum of its proper divisors (12978895882).

21028973558 is a wasteful number, since it uses less digits than its factorization.

21028973558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54932.

The product of its (nonzero) digits is 1209600, while the sum is 50.

The spelling of 21028973558 in words is "twenty-one billion, twenty-eight million, nine hundred seventy-three thousand, five hundred fifty-eight".