21625810 has 8 divisors (see below), whose sum is σ = 38926476. Its totient is φ = 8650320.

The previous prime is 21625787. The next prime is 21625811. The reversal of 21625810 is 1852612.

It can be written as a sum of positive squares in 2 ways, for example, as 19811401 + 1814409 = 4451^2 + 1347^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21625810² = 935351316312200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21625811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1081281 + ... + 1081300.

Almost surely, 2^21625810 is an apocalyptic number.

21625810 is a deficient number, since it is larger than the sum of its proper divisors (17300666).

21625810 is a wasteful number, since it uses less digits than its factorization.

21625810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162588.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 21625810 is about 4650.3559003586. The cubic root of 21625810 is about 278.6062112418.

The spelling of 21625810 in words is "twenty-one million, six hundred twenty-five thousand, eight hundred ten".