21450370 has 16 divisors (see below), whose sum is σ = 38787840. Its totient is φ = 8540784.

The previous prime is 21450367. The next prime is 21450389. The reversal of 21450370 is 7305412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2580 + ... + 7039.

It is an arithmetic number, because the mean of its divisors is an integer number (2424240).

Almost surely, 2^21450370 is an apocalyptic number.

21450370 is a deficient number, since it is larger than the sum of its proper divisors (17337470).

21450370 is a wasteful number, since it uses less digits than its factorization.

21450370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9849.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21450370 is about 4631.4544151918. The cubic root of 21450370 is about 277.8507644061.

Adding to 21450370 its reverse (7305412), we get a palindrome (28755782).

The spelling of 21450370 in words is "twenty-one million, four hundred fifty thousand, three hundred seventy".