21250253434633 has 4 divisors (see below), whose sum is σ = 21824584608580. Its totient is φ = 20675922260688.

The previous prime is 21250253434607. The next prime is 21250253434723. The reversal of 21250253434633 is 33643435205212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16187811934464 + 5062441500169 = 4023408^2 + 2249987^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250253434633 - 2⁵ = 21250253434601 is a prime.

It is a super-2 number, since 2×21250253434633² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21250253434633.

It is not an unprimeable number, because it can be changed into a prime (21250253434603) 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, 287165586918 + ... + 287165586991.

It is an arithmetic number, because the mean of its divisors is an integer number (5456146152145).

Almost surely, 2^{21250253434633} is an apocalyptic number.

It is an amenable number.

21250253434633 is a deficient number, since it is larger than the sum of its proper divisors (574331173947).

21250253434633 is an equidigital number, since it uses as much as digits as its factorization.

21250253434633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574331173946.

The product of its (nonzero) digits is 1555200, while the sum is 43.

Adding to 21250253434633 its reverse (33643435205212), we get a palindrome (54893688639845).

The spelling of 21250253434633 in words is "twenty-one trillion, two hundred fifty billion, two hundred fifty-three million, four hundred thirty-four thousand, six hundred thirty-three".