21431040400 has 240 divisors, whose sum is σ = 64546725888. Its totient is φ = 6643008000.

The previous prime is 21431040383. The next prime is 21431040437. The reversal of 21431040400 is 404013412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5880979 + ... + 5884621.

Almost surely, 2^21431040400 is an apocalyptic number.

21431040400 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 21431040400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32273362944).

21431040400 is an abundant number, since it is smaller than the sum of its proper divisors (43115685488).

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

21431040400 is a wasteful number, since it uses less digits than its factorization.

21431040400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3870 (or 3859 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21431040400 its reverse (404013412), we get a palindrome (21835053812).

The spelling of 21431040400 in words is "twenty-one billion, four hundred thirty-one million, forty thousand, four hundred".