21475848840 has 32 divisors (see below), whose sum is σ = 64427546880. Its totient is φ = 5726892992.

The previous prime is 21475848829. The next prime is 21475848841. The reversal of 21475848840 is 4884857412.

It is a happy number.

It is a super-2 number, since 2×21475848840² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21475848841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89482584 + ... + 89482823.

It is an arithmetic number, because the mean of its divisors is an integer number (2013360840).

Almost surely, 2^21475848840 is an apocalyptic number.

21475848840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21475848840 is an abundant number, since it is smaller than the sum of its proper divisors (42951698040).

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

21475848840 is a wasteful number, since it uses less digits than its factorization.

21475848840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178965421 (or 178965417 counting only the distinct ones).

The product of its (nonzero) digits is 2293760, while the sum is 51.

The spelling of 21475848840 in words is "twenty-one billion, four hundred seventy-five million, eight hundred forty-eight thousand, eight hundred forty".