21406047852 has 96 divisors (see below), whose sum is σ = 57372521472. Its totient is φ = 6085069056.

The previous prime is 21406047841. The next prime is 21406047857. The reversal of 21406047852 is 25874060412.

It is a super-2 number, since 2×21406047852² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21406047852.

It is not an unprimeable number, because it can be changed into a prime (21406047857) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21775753 + ... + 21776735.

It is an arithmetic number, because the mean of its divisors is an integer number (597630432).

Almost surely, 2^21406047852 is an apocalyptic number.

It is an amenable number.

21406047852 is an abundant number, since it is smaller than the sum of its proper divisors (35966473620).

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

21406047852 is a wasteful number, since it uses less digits than its factorization.

21406047852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2047 (or 2045 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 39.

The spelling of 21406047852 in words is "twenty-one billion, four hundred six million, forty-seven thousand, eight hundred fifty-two".