21153131406 has 48 divisors (see below), whose sum is σ = 50817984048. Its totient is φ = 6304953600.

The previous prime is 21153131401. The next prime is 21153131407. The reversal of 21153131406 is 60413135112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21153131406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21153131401) 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 23 ways as a sum of consecutive naturals, for example, 863611 + ... + 887766.

It is an arithmetic number, because the mean of its divisors is an integer number (1058708001).

Almost surely, 2^21153131406 is an apocalyptic number.

21153131406 is an abundant number, since it is smaller than the sum of its proper divisors (29664852642).

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

21153131406 is a wasteful number, since it uses less digits than its factorization.

21153131406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751457 (or 1751454 counting only the distinct ones).

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

Adding to 21153131406 its reverse (60413135112), we get a palindrome (81566266518).

The spelling of 21153131406 in words is "twenty-one billion, one hundred fifty-three million, one hundred thirty-one thousand, four hundred six".