21251404531602 has 256 divisors, whose sum is σ = 58451766912000. Its totient is φ = 5701053818880.

The previous prime is 21251404531589. The next prime is 21251404531613. The reversal of 21251404531602 is 20613540415212.

21251404531602 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 1 + 4 + 0 + 45 + 3 + 1 + 602 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 132481798 + ... + 132642110.

It is an arithmetic number, because the mean of its divisors is an integer number (228327214500).

Almost surely, 2^{21251404531602} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21251404531602, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29225883456000).

21251404531602 is an abundant number, since it is smaller than the sum of its proper divisors (37200362380398).

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

21251404531602 is a wasteful number, since it uses less digits than its factorization.

21251404531602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160783 (or 160763 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

Adding to 21251404531602 its reverse (20613540415212), we get a palindrome (41864944946814).

The spelling of 21251404531602 in words is "twenty-one trillion, two hundred fifty-one billion, four hundred four million, five hundred thirty-one thousand, six hundred two".