21220120556245 has 64 divisors (see below), whose sum is σ = 27787444715520. Its totient is φ = 15463411826688.

The previous prime is 21220120556209. The next prime is 21220120556269. The reversal of 21220120556245 is 54265502102212.

It is a cyclic number.

It is not a de Polignac number, because 21220120556245 - 2²¹ = 21220118459093 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2085100597 + ... + 2085110773.

It is an arithmetic number, because the mean of its divisors is an integer number (434178823680).

Almost surely, 2^{21220120556245} is an apocalyptic number.

It is an amenable number.

21220120556245 is a deficient number, since it is larger than the sum of its proper divisors (6567324159275).

21220120556245 is a wasteful number, since it uses less digits than its factorization.

21220120556245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11654.

The product of its (nonzero) digits is 96000, while the sum is 37.

Adding to 21220120556245 its reverse (54265502102212), we get a palindrome (75485622658457).

The spelling of 21220120556245 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty million, five hundred fifty-six thousand, two hundred forty-five".