21000465388 has 96 divisors (see below), whose sum is σ = 46095920640. Its totient is φ = 8170606080.

The previous prime is 21000465379. The next prime is 21000465403. The reversal of 21000465388 is 88356400012.

It is a happy 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, 1203768 + ... + 1221088.

It is an arithmetic number, because the mean of its divisors is an integer number (480165840).

Almost surely, 2^21000465388 is an apocalyptic number.

21000465388 is a gapful number since it is divisible by the number (28) 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 21000465388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23047960320).

21000465388 is an abundant number, since it is smaller than the sum of its proper divisors (25095455252).

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

21000465388 is a wasteful number, since it uses less digits than its factorization.

21000465388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17447 (or 17445 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The spelling of 21000465388 in words is "twenty-one billion, four hundred sixty-five thousand, three hundred eighty-eight".