21153550000 has 120 divisors (see below), whose sum is σ = 55886516784. Its totient is φ = 7692000000.

The previous prime is 21153549997. The next prime is 21153550013. The reversal of 21153550000 is 5535112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 530770 + ... + 569230.

Almost surely, 2^21153550000 is an apocalyptic number.

21153550000 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 21153550000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27943258392).

21153550000 is an abundant number, since it is smaller than the sum of its proper divisors (34732966784).

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

21153550000 is an equidigital number, since it uses as much as digits as its factorization.

21153550000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38505 (or 38479 counting only the distinct ones).

The product of its (nonzero) digits is 750, while the sum is 22.

The spelling of 21153550000 in words is "twenty-one billion, one hundred fifty-three million, five hundred fifty thousand".