21552770 has 16 divisors (see below), whose sum is σ = 41077368. Its totient is φ = 8113920.

The previous prime is 21552767. The next prime is 21552779. The reversal of 21552770 is 7725512.

It can be written as a sum of positive squares in 4 ways, for example, as 18156121 + 3396649 = 4261^2 + 1843^2 .

It is not an unprimeable number, because it can be changed into a prime (21552779) by changing a digit.

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, 63221 + ... + 63560.

Almost surely, 2^21552770 is an apocalyptic number.

21552770 is a deficient number, since it is larger than the sum of its proper divisors (19524598).

21552770 is a wasteful number, since it uses less digits than its factorization.

21552770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126805.

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 21552770 is about 4642.4960958519. The cubic root of 21552770 is about 278.2921983345.

It can be divided in two parts, 21552 and 770, that added together give a palindrome (22322).

The spelling of 21552770 in words is "twenty-one million, five hundred fifty-two thousand, seven hundred seventy".