21430443240 has 64 divisors (see below), whose sum is σ = 71434814400. Its totient is φ = 5714784576.

The previous prime is 21430443227. The next prime is 21430443247. The reversal of 21430443240 is 4234403412.

It is a happy number.

21430443240 is a `hidden beast` number, since 214 + 3 + 0 + 443 + 2 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21430443247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9920422 + ... + 9922581.

It is an arithmetic number, because the mean of its divisors is an integer number (1116168975).

Almost surely, 2^21430443240 is an apocalyptic number.

21430443240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21430443240 is an abundant number, since it is smaller than the sum of its proper divisors (50004371160).

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

21430443240 is a wasteful number, since it uses less digits than its factorization.

21430443240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19843023 (or 19843013 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 21430443240 its reverse (4234403412), we get a palindrome (25664846652).

The spelling of 21430443240 in words is "twenty-one billion, four hundred thirty million, four hundred forty-three thousand, two hundred forty".