21897010 has 16 divisors (see below), whose sum is σ = 39778200. Its totient is φ = 8678016.

The previous prime is 21896999. The next prime is 21897011. The reversal of 21897010 is 1079812.

It can be written as a sum of positive squares in 4 ways, for example, as 15531481 + 6365529 = 3941^2 + 2523^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21897010.

It is not an unprimeable number, because it can be changed into a prime (21897011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8955 + ... + 11134.

Almost surely, 2^21897010 is an apocalyptic number.

21897010 is a deficient number, since it is larger than the sum of its proper divisors (17881190).

21897010 is a wasteful number, since it uses less digits than its factorization.

21897010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20205.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 21897010 is about 4679.4241098665. The cubic root of 21897010 is about 279.7660034827.

The spelling of 21897010 in words is "twenty-one million, eight hundred ninety-seven thousand, ten".