21251051422 has 4 divisors (see below), whose sum is σ = 31876577136. Its totient is φ = 10625525710.

The previous prime is 21251051401. The next prime is 21251051431. The reversal of 21251051422 is 22415015212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5312762854 + ... + 5312762857.

It is an arithmetic number, because the mean of its divisors is an integer number (7969144284).

Almost surely, 2^21251051422 is an apocalyptic number.

21251051422 is a deficient number, since it is larger than the sum of its proper divisors (10625525714).

21251051422 is a wasteful number, since it uses less digits than its factorization.

21251051422 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10625525713.

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21251051422 its reverse (22415015212), we get a palindrome (43666066634).

The spelling of 21251051422 in words is "twenty-one billion, two hundred fifty-one million, fifty-one thousand, four hundred twenty-two".