21366440510340 has 24 divisors (see below), whose sum is σ = 59826033429120. Its totient is φ = 5697717469408.

The previous prime is 21366440510267. The next prime is 21366440510377. The reversal of 21366440510340 is 4301504466312.

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, 178053670860 + ... + 178053670979.

It is an arithmetic number, because the mean of its divisors is an integer number (2492751392880).

Almost surely, 2^{21366440510340} is an apocalyptic number.

21366440510340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21366440510340 is an abundant number, since it is smaller than the sum of its proper divisors (38459592918780).

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

21366440510340 is a wasteful number, since it uses less digits than its factorization.

21366440510340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356107341851 (or 356107341849 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 39.

Adding to 21366440510340 its reverse (4301504466312), we get a palindrome (25667944976652).

The spelling of 21366440510340 in words is "twenty-one trillion, three hundred sixty-six billion, four hundred forty million, five hundred ten thousand, three hundred forty".