21431102240 has 24 divisors (see below), whose sum is σ = 50630979420. Its totient is φ = 8572440832.

The previous prime is 21431102221. The next prime is 21431102243. The reversal of 21431102240 is 4220113412.

It can be written as a sum of positive squares in 2 ways, for example, as 21319504144 + 111598096 = 146012^2 + 10564^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21431102243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66972035 + ... + 66972354.

Almost surely, 2^21431102240 is an apocalyptic number.

21431102240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21431102240 is an abundant number, since it is smaller than the sum of its proper divisors (29199877180).

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

21431102240 is a wasteful number, since it uses less digits than its factorization.

21431102240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133944404 (or 133944396 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21431102240 its reverse (4220113412), we get a palindrome (25651215652).

The spelling of 21431102240 in words is "twenty-one billion, four hundred thirty-one million, one hundred two thousand, two hundred forty".