21251042110346 has 4 divisors (see below), whose sum is σ = 31876563165522. Its totient is φ = 10625521055172.

The previous prime is 21251042110327. The next prime is 21251042110381. The reversal of 21251042110346 is 64301124015212.

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

It can be written as a sum of positive squares in only one way, i.e., 21176204301121 + 74837809225 = 4601761^2 + 273565^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5312760527585 + ... + 5312760527588.

Almost surely, 2^{21251042110346} is an apocalyptic number.

21251042110346 is a deficient number, since it is larger than the sum of its proper divisors (10625521055176).

21251042110346 is a wasteful number, since it uses less digits than its factorization.

21251042110346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10625521055175.

The product of its (nonzero) digits is 11520, while the sum is 32.

Adding to 21251042110346 its reverse (64301124015212), we get a palindrome (85552166125558).

The spelling of 21251042110346 in words is "twenty-one trillion, two hundred fifty-one billion, forty-two million, one hundred ten thousand, three hundred forty-six".