21645350 has 12 divisors (see below), whose sum is σ = 40260444. Its totient is φ = 8658120.

The previous prime is 21645343. The next prime is 21645373. The reversal of 21645350 is 5354612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216404 + ... + 216503.

It is an arithmetic number, because the mean of its divisors is an integer number (3355037).

Almost surely, 2^21645350 is an apocalyptic number.

21645350 is a deficient number, since it is larger than the sum of its proper divisors (18615094).

21645350 is a wasteful number, since it uses less digits than its factorization.

21645350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432919 (or 432914 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21645350 is about 4652.4563404722. The cubic root of 21645350 is about 278.6900975264.

Adding to 21645350 its reverse (5354612), we get a palindrome (26999962).

The spelling of 21645350 in words is "twenty-one million, six hundred forty-five thousand, three hundred fifty".