21435215556 has 48 divisors (see below), whose sum is σ = 51941715840. Its totient is φ = 6871818240.

The previous prime is 21435215551. The next prime is 21435215569. The reversal of 21435215556 is 65551253412.

It is a super-4 number, since 4×21435215556⁴ (a number of 42 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (21435215551) 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, 30400 + ... + 209271.

It is an arithmetic number, because the mean of its divisors is an integer number (1082119080).

Almost surely, 2^21435215556 is an apocalyptic number.

It is an amenable number.

21435215556 is an abundant number, since it is smaller than the sum of its proper divisors (30506500284).

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

21435215556 is a wasteful number, since it uses less digits than its factorization.

21435215556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239964 (or 239962 counting only the distinct ones).

The product of its digits is 180000, while the sum is 39.

Adding to 21435215556 its reverse (65551253412), we get a palindrome (86986468968).

The spelling of 21435215556 in words is "twenty-one billion, four hundred thirty-five million, two hundred fifteen thousand, five hundred fifty-six".