21236851228831 has 48 divisors (see below), whose sum is σ = 25358896221120. Its totient is φ = 17722393920000.

The previous prime is 21236851228799. The next prime is 21236851228837. The reversal of 21236851228831 is 13882215863212.

It is not a de Polignac number, because 21236851228831 - 2⁵ = 21236851228799 is a prime.

It is a super-2 number, since 2×21236851228831² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21236851228837) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3387594765 + ... + 3387601033.

It is an arithmetic number, because the mean of its divisors is an integer number (528310337940).

Almost surely, 2^{21236851228831} is an apocalyptic number.

21236851228831 is a deficient number, since it is larger than the sum of its proper divisors (4122044992289).

21236851228831 is a wasteful number, since it uses less digits than its factorization.

21236851228831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9536 (or 9529 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 52.

The spelling of 21236851228831 in words is "twenty-one trillion, two hundred thirty-six billion, eight hundred fifty-one million, two hundred twenty-eight thousand, eight hundred thirty-one".