21143421456 has 40 divisors (see below), whose sum is σ = 54631086720. Its totient is φ = 7046441856.

The previous prime is 21143421359. The next prime is 21143421469. The reversal of 21143421456 is 65412434112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225006 + ... + 304818.

It is an arithmetic number, because the mean of its divisors is an integer number (1365777168).

Almost surely, 2^21143421456 is an apocalyptic number.

It is an amenable number.

21143421456 is an abundant number, since it is smaller than the sum of its proper divisors (33487665264).

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

21143421456 is a wasteful number, since it uses less digits than its factorization.

21143421456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85343 (or 85337 counting only the distinct ones).

The product of its digits is 23040, while the sum is 33.

Adding to 21143421456 its reverse (65412434112), we get a palindrome (86555855568).

The spelling of 21143421456 in words is "twenty-one billion, one hundred forty-three million, four hundred twenty-one thousand, four hundred fifty-six".