21253240431235 has 8 divisors (see below), whose sum is σ = 26125934579136. Its totient is φ = 16587894970560.

The previous prime is 21253240431209. The next prime is 21253240431257. The reversal of 21253240431235 is 53213404235212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21253240431235 - 2⁷ = 21253240431107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21253240431194 and 21253240431203.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51837171579 + ... + 51837171988.

It is an arithmetic number, because the mean of its divisors is an integer number (3265741822392).

Almost surely, 2^{21253240431235} is an apocalyptic number.

21253240431235 is a deficient number, since it is larger than the sum of its proper divisors (4872694147901).

21253240431235 is a wasteful number, since it uses less digits than its factorization.

21253240431235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103674343613.

The product of its (nonzero) digits is 172800, while the sum is 37.

Adding to 21253240431235 its reverse (53213404235212), we get a palindrome (74466644666447).

The spelling of 21253240431235 in words is "twenty-one trillion, two hundred fifty-three billion, two hundred forty million, four hundred thirty-one thousand, two hundred thirty-five".