21201435250 has 64 divisors (see below), whose sum is σ = 42129940320. Its totient is φ = 7961548800.

The previous prime is 21201435223. The next prime is 21201435253. The reversal of 21201435250 is 5253410212.

It can be written as a sum of positive squares in 16 ways, for example, as 1697357601 + 19504077649 = 41199^2 + 139657^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21201435253) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1732152 + ... + 1744348.

Almost surely, 2^21201435250 is an apocalyptic number.

21201435250 is a deficient number, since it is larger than the sum of its proper divisors (20928505070).

21201435250 is a wasteful number, since it uses less digits than its factorization.

21201435250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12640 (or 12630 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21201435250 its reverse (5253410212), we get a palindrome (26454845462).

The spelling of 21201435250 in words is "twenty-one billion, two hundred one million, four hundred thirty-five thousand, two hundred fifty".