21273906852 has 288 divisors, whose sum is σ = 65208729600. Its totient is φ = 5974119360.

The previous prime is 21273906803. The next prime is 21273906859. The reversal of 21273906852 is 25860937212.

It is a super-2 number, since 2×21273906852² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21273906798 and 21273906807.

It is not an unprimeable number, because it can be changed into a prime (21273906859) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11668813 + ... + 11670635.

It is an arithmetic number, because the mean of its divisors is an integer number (226419200).

Almost surely, 2^21273906852 is an apocalyptic number.

21273906852 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21273906852, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32604364800).

21273906852 is an abundant number, since it is smaller than the sum of its proper divisors (43934822748).

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

21273906852 is a wasteful number, since it uses less digits than its factorization.

21273906852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1924 (or 1905 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 21273906852 in words is "twenty-one billion, two hundred seventy-three million, nine hundred six thousand, eight hundred fifty-two".