21010354452 has 84 divisors (see below), whose sum is σ = 55188774676. Its totient is φ = 6995600640.

The previous prime is 21010354447. The next prime is 21010354457. The reversal of 21010354452 is 25445301012.

21010354452 is a `hidden beast` number, since 2 + 10 + 103 + 544 + 5 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (21010354447) and next prime (21010354457).

It can be written as a sum of positive squares in 2 ways, for example, as 18356456196 + 2653898256 = 135486^2 + 51516^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010354457) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 2973708 + ... + 2980764.

Almost surely, 2^21010354452 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 21010354452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27594387338).

21010354452 is an abundant number, since it is smaller than the sum of its proper divisors (34178420224).

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

21010354452 is a wasteful number, since it uses less digits than its factorization.

21010354452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8100 (or 8083 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21010354452 its reverse (25445301012), we get a palindrome (46455655464).

The spelling of 21010354452 in words is "twenty-one billion, ten million, three hundred fifty-four thousand, four hundred fifty-two".