21251235126 has 32 divisors (see below), whose sum is σ = 46371621888. Its totient is φ = 6439033440.

The previous prime is 21251235079. The next prime is 21251235143. The reversal of 21251235126 is 62153215212.

It is a super-2 number, since 2×21251235126² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21251235093 and 21251235102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 941691 + ... + 963993.

It is an arithmetic number, because the mean of its divisors is an integer number (1449113184).

Almost surely, 2^21251235126 is an apocalyptic number.

21251235126 is an abundant number, since it is smaller than the sum of its proper divisors (25120386762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21251235126 is a wasteful number, since it uses less digits than its factorization.

21251235126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36756.

The product of its digits is 7200, while the sum is 30.

The spelling of 21251235126 in words is "twenty-one billion, two hundred fifty-one million, two hundred thirty-five thousand, one hundred twenty-six".