21303400340 has 12 divisors (see below), whose sum is σ = 44737140756. Its totient is φ = 8521360128.

The previous prime is 21303400301. The next prime is 21303400367. The reversal of 21303400340 is 4300430312.

It can be written as a sum of positive squares in 2 ways, for example, as 16416271876 + 4887128464 = 128126^2 + 69908^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1065170017 = 21303400340 / (2 + 1 + 3 + 0 + 3 + 4 + 0 + 0 + 3 + 4 + 0).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 532584989 + ... + 532585028.

It is an arithmetic number, because the mean of its divisors is an integer number (3728095063).

Almost surely, 2^21303400340 is an apocalyptic number.

21303400340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21303400340 is an abundant number, since it is smaller than the sum of its proper divisors (23433740416).

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

21303400340 is a wasteful number, since it uses less digits than its factorization.

21303400340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1065170026 (or 1065170024 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

Adding to 21303400340 its reverse (4300430312), we get a palindrome (25603830652).

The spelling of 21303400340 in words is "twenty-one billion, three hundred three million, four hundred thousand, three hundred forty".