21210340550 has 24 divisors (see below), whose sum is σ = 45087124656. Its totient is φ = 7272116640.

The previous prime is 21210340531. The next prime is 21210340573. The reversal of 21210340550 is 5504301212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30300137 + ... + 30300836.

It is an arithmetic number, because the mean of its divisors is an integer number (1878630194).

Almost surely, 2^21210340550 is an apocalyptic number.

21210340550 is an abundant number, since it is smaller than the sum of its proper divisors (23876784106).

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

21210340550 is a wasteful number, since it uses less digits than its factorization.

21210340550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60600992 (or 60600987 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 21210340550 its reverse (5504301212), we get a palindrome (26714641762).

The spelling of 21210340550 in words is "twenty-one billion, two hundred ten million, three hundred forty thousand, five hundred fifty".