21012202340 has 24 divisors (see below), whose sum is σ = 45201861432. Its totient is φ = 8199883520.

The previous prime is 21012202339. The next prime is 21012202417. The reversal of 21012202340 is 4320221012.

It can be written as a sum of positive squares in 4 ways, for example, as 140043556 + 20872158784 = 11834^2 + 144472^2 .

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, 12811499 + ... + 12813138.

It is an arithmetic number, because the mean of its divisors is an integer number (1883410893).

Almost surely, 2^21012202340 is an apocalyptic number.

21012202340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012202340 is an abundant number, since it is smaller than the sum of its proper divisors (24189659092).

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

21012202340 is a wasteful number, since it uses less digits than its factorization.

21012202340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25624687 (or 25624685 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21012202340 its reverse (4320221012), we get a palindrome (25332423352).

The spelling of 21012202340 in words is "twenty-one billion, twelve million, two hundred two thousand, three hundred forty".