21006623000 has 128 divisors (see below), whose sum is σ = 55354890240. Its totient is φ = 7392240000.

The previous prime is 21006622997. The next prime is 21006623021. The reversal of 21006623000 is 32660012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 310199 + ... + 371801.

It is an arithmetic number, because the mean of its divisors is an integer number (432460080).

Almost surely, 2^21006623000 is an apocalyptic number.

21006623000 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 21006623000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27677445120).

21006623000 is an abundant number, since it is smaller than the sum of its proper divisors (34348267240).

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

21006623000 is a wasteful number, since it uses less digits than its factorization.

21006623000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61666 (or 61652 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The spelling of 21006623000 in words is "twenty-one billion, six million, six hundred twenty-three thousand".