21189707400 has 192 divisors, whose sum is σ = 67688524800. Its totient is φ = 5480949760.

The previous prime is 21189707387. The next prime is 21189707411. The reversal of 21189707400 is 470798112.

It is a super-2 number, since 2×21189707400² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2826457 + ... + 2833943.

It is an arithmetic number, because the mean of its divisors is an integer number (352544400).

Almost surely, 2^21189707400 is an apocalyptic number.

21189707400 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 21189707400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33844262400).

21189707400 is an abundant number, since it is smaller than the sum of its proper divisors (46498817400).

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

21189707400 is a wasteful number, since it uses less digits than its factorization.

21189707400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7648 (or 7639 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 39.

The spelling of 21189707400 in words is "twenty-one billion, one hundred eighty-nine million, seven hundred seven thousand, four hundred".