21061343250 has 256 divisors, whose sum is σ = 62154892800. Its totient is φ = 5262796800.

The previous prime is 21061343201. The next prime is 21061343273. The reversal of 21061343250 is 5234316012.

21061343250 is a `hidden beast` number, since 2 + 1 + 0 + 613 + 43 + 2 + 5 + 0 = 666.

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

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, 12439404 + ... + 12441096.

It is an arithmetic number, because the mean of its divisors is an integer number (242792550).

Almost surely, 2^21061343250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21061343250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31077446400).

21061343250 is an abundant number, since it is smaller than the sum of its proper divisors (41093549550).

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

21061343250 is a wasteful number, since it uses less digits than its factorization.

21061343250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1835 (or 1819 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 21061343250 its reverse (5234316012), we get a palindrome (26295659262).

The spelling of 21061343250 in words is "twenty-one billion, sixty-one million, three hundred forty-three thousand, two hundred fifty".