21098689920 has 1024 divisors, whose sum is σ = 94684723200. Its totient is φ = 4313088000.

The previous prime is 21098689903. The next prime is 21098689949. The reversal of 21098689920 is 2998689012.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 134386482 + ... + 134386638.

It is an arithmetic number, because the mean of its divisors is an integer number (92465550).

Almost surely, 2^21098689920 is an apocalyptic number.

21098689920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21098689920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47342361600).

21098689920 is an abundant number, since it is smaller than the sum of its proper divisors (73586033280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21098689920 is a wasteful number, since it uses less digits than its factorization.

21098689920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 21098689920 in words is "twenty-one billion, ninety-eight million, six hundred eighty-nine thousand, nine hundred twenty".