21551170 has 16 divisors (see below), whose sum is σ = 39695040. Its totient is φ = 8419824.

The previous prime is 21551143. The next prime is 21551171. The reversal of 21551170 is 7115512.

It is not an unprimeable number, because it can be changed into a prime (21551171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24630 + ... + 25489.

It is an arithmetic number, because the mean of its divisors is an integer number (2480940).

Almost surely, 2^21551170 is an apocalyptic number.

21551170 is a deficient number, since it is larger than the sum of its proper divisors (18143870).

21551170 is a wasteful number, since it uses less digits than its factorization.

21551170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50169.

The product of its (nonzero) digits is 350, while the sum is 22.

The square root of 21551170 is about 4642.3237715610. The cubic root of 21551170 is about 278.2853116940.

Adding to 21551170 its reverse (7115512), we get a palindrome (28666682).

The spelling of 21551170 in words is "twenty-one million, five hundred fifty-one thousand, one hundred seventy".