21770064 has 60 divisors (see below), whose sum is σ = 64517076. Its totient is φ = 6829056.

The previous prime is 21770059. The next prime is 21770087. The reversal of 21770064 is 46007712.

It can be written as a sum of positive squares in 2 ways, for example, as 9659664 + 12110400 = 3108^2 + 3480^2 .

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 1999 + ... + 6894.

Almost surely, 2^21770064 is an apocalyptic number.

21770064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21770064 is an abundant number, since it is smaller than the sum of its proper divisors (42747012).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21770064 is a wasteful number, since it uses less digits than its factorization.

21770064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8924 (or 8915 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 21770064 is about 4665.8401172779. The cubic root of 21770064 is about 279.2243156903.

Adding to 21770064 its reverse (46007712), we get a palindrome (67777776).

The spelling of 21770064 in words is "twenty-one million, seven hundred seventy thousand, sixty-four".