21402250 has 32 divisors (see below), whose sum is σ = 40772160. Its totient is φ = 8410000.

The previous prime is 21402239. The next prime is 21402253. The reversal of 21402250 is 5220412.

It is not an unprimeable number, because it can be changed into a prime (21402253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14025 + ... + 15475.

It is an arithmetic number, because the mean of its divisors is an integer number (1274130).

Almost surely, 2^21402250 is an apocalyptic number.

21402250 is a deficient number, since it is larger than the sum of its proper divisors (19369910).

21402250 is a wasteful number, since it uses less digits than its factorization.

21402250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527 (or 1517 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21402250 is about 4626.2565860531. The cubic root of 21402250 is about 277.6428396459.

Adding to 21402250 its reverse (5220412), we get a palindrome (26622662).

The spelling of 21402250 in words is "twenty-one million, four hundred two thousand, two hundred fifty".