21002104250 has 32 divisors (see below), whose sum is σ = 39469040208. Its totient is φ = 8368128000.

The previous prime is 21002104237. The next prime is 21002104261. The reversal of 21002104250 is 5240120012.

It can be written as a sum of positive squares in 8 ways, for example, as 8537944801 + 12464159449 = 92401^2 + 111643^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99191 + ... + 227690.

Almost surely, 2^21002104250 is an apocalyptic number.

21002104250 is a deficient number, since it is larger than the sum of its proper divisors (18466935958).

21002104250 is a wasteful number, since it uses less digits than its factorization.

21002104250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327155 (or 327145 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

Adding to 21002104250 its reverse (5240120012), we get a palindrome (26242224262).

The spelling of 21002104250 in words is "twenty-one billion, two million, one hundred four thousand, two hundred fifty".