21304542340 has 12 divisors (see below), whose sum is σ = 44739538956. Its totient is φ = 8521816928.

The previous prime is 21304542323. The next prime is 21304542359. The reversal of 21304542340 is 4324540312.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4941527616 + 16363014724 = 70296^2 + 127918^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21304542299 and 21304542308.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 532613539 + ... + 532613578.

It is an arithmetic number, because the mean of its divisors is an integer number (3728294913).

Almost surely, 2^21304542340 is an apocalyptic number.

21304542340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21304542340 is an abundant number, since it is smaller than the sum of its proper divisors (23434996616).

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

21304542340 is a wasteful number, since it uses less digits than its factorization.

21304542340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065227126 (or 1065227124 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 28.

The spelling of 21304542340 in words is "twenty-one billion, three hundred four million, five hundred forty-two thousand, three hundred forty".