21398903400 has 192 divisors, whose sum is σ = 76076380800. Its totient is φ = 4874204160.

The previous prime is 21398903381. The next prime is 21398903401. The reversal of 21398903400 is 430989312.

It is not an unprimeable number, because it can be changed into a prime (21398903401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1221906 + ... + 1239294.

It is an arithmetic number, because the mean of its divisors is an integer number (396231150).

Almost surely, 2^21398903400 is an apocalyptic number.

21398903400 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 21398903400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38038190400).

21398903400 is an abundant number, since it is smaller than the sum of its proper divisors (54677477400).

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

21398903400 is a wasteful number, since it uses less digits than its factorization.

21398903400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17708 (or 17699 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The spelling of 21398903400 in words is "twenty-one billion, three hundred ninety-eight million, nine hundred three thousand, four hundred".