21255220146553 has 4 divisors (see below), whose sum is σ = 22373915943760. Its totient is φ = 20136524349348.

The previous prime is 21255220146551. The next prime is 21255220146557. The reversal of 21255220146553 is 35564102255212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21255220146553 - 2¹ = 21255220146551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21255220146551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 559347898575 + ... + 559347898612.

It is an arithmetic number, because the mean of its divisors is an integer number (5593478985940).

Almost surely, 2^{21255220146553} is an apocalyptic number.

It is an amenable number.

21255220146553 is a deficient number, since it is larger than the sum of its proper divisors (1118695797207).

21255220146553 is a wasteful number, since it uses less digits than its factorization.

21255220146553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118695797206.

The product of its (nonzero) digits is 720000, while the sum is 43.

The spelling of 21255220146553 in words is "twenty-one trillion, two hundred fifty-five billion, two hundred twenty million, one hundred forty-six thousand, five hundred fifty-three".