21253212266545 has 16 divisors (see below), whose sum is σ = 29625086515968. Its totient is φ = 14334719279040.

The previous prime is 21253212266521. The next prime is 21253212266549. The reversal of 21253212266545 is 54566221235212.

It is not a de Polignac number, because 21253212266545 - 2⁷ = 21253212266417 is a prime.

It is a super-2 number, since 2×21253212266545² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21253212266495 and 21253212266504.

It is not an unprimeable number, because it can be changed into a prime (21253212266549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4977330949 + ... + 4977335218.

It is an arithmetic number, because the mean of its divisors is an integer number (1851567907248).

Almost surely, 2^{21253212266545} is an apocalyptic number.

It is an amenable number.

21253212266545 is a deficient number, since it is larger than the sum of its proper divisors (8371874249423).

21253212266545 is an equidigital number, since it uses as much as digits as its factorization.

21253212266545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9954666240.

The product of its digits is 1728000, while the sum is 46.

The spelling of 21253212266545 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred twelve million, two hundred sixty-six thousand, five hundred forty-five".