21311401356 has 72 divisors (see below), whose sum is σ = 61662785184. Its totient is φ = 6079426560.

The previous prime is 21311401351. The next prime is 21311401367. The reversal of 21311401356 is 65310411312.

It is a happy number.

21311401356 is a `hidden beast` number, since 213 + 11 + 401 + 35 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (21311401351) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95566 + ... + 227498.

It is an arithmetic number, because the mean of its divisors is an integer number (856427572).

Almost surely, 2^21311401356 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21311401356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30831392592).

21311401356 is an abundant number, since it is smaller than the sum of its proper divisors (40351383828).

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

21311401356 is a wasteful number, since it uses less digits than its factorization.

21311401356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132591 (or 132586 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

Adding to 21311401356 its reverse (65310411312), we get a palindrome (86621812668).

The spelling of 21311401356 in words is "twenty-one billion, three hundred eleven million, four hundred one thousand, three hundred fifty-six".