21253213065511 has 16 divisors (see below), whose sum is σ = 24665851793664. Its totient is φ = 17935577198784.

The previous prime is 21253213065509. The next prime is 21253213065613. The reversal of 21253213065511 is 11556031235212.

It is not a de Polignac number, because 21253213065511 - 2¹ = 21253213065509 is a prime.

It is a super-2 number, since 2×21253213065511² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253213068511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36649621 + ... + 37225006.

It is an arithmetic number, because the mean of its divisors is an integer number (1541615737104).

Almost surely, 2^{21253213065511} is an apocalyptic number.

21253213065511 is a deficient number, since it is larger than the sum of its proper divisors (3412638728153).

21253213065511 is an equidigital number, since it uses as much as digits as its factorization.

21253213065511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73875270.

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 21253213065511 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred thirteen million, sixty-five thousand, five hundred eleven".