21725126051 has 4 divisors (see below), whose sum is σ = 21816026400. Its totient is φ = 21634225704.

The previous prime is 21725126041. The next prime is 21725126119. The reversal of 21725126051 is 15062152712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21725126051 is a prime.

It is a super-2 number, since 2×21725126051² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21725125999 and 21725126017.

It is not an unprimeable number, because it can be changed into a prime (21725126021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45449816 + ... + 45450293.

It is an arithmetic number, because the mean of its divisors is an integer number (5454006600).

Almost surely, 2^21725126051 is an apocalyptic number.

21725126051 is a deficient number, since it is larger than the sum of its proper divisors (90900349).

21725126051 is an equidigital number, since it uses as much as digits as its factorization.

21725126051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90900348.

The product of its (nonzero) digits is 8400, while the sum is 32.

Adding to 21725126051 its reverse (15062152712), we get a palindrome (36787278763).

The spelling of 21725126051 in words is "twenty-one billion, seven hundred twenty-five million, one hundred twenty-six thousand, fifty-one".