21250010 has 8 divisors (see below), whose sum is σ = 38250036. Its totient is φ = 8500000.

The previous prime is 21250007. The next prime is 21250039. The reversal of 21250010 is 1005212.

It can be written as a sum of positive squares in 2 ways, for example, as 20187049 + 1062961 = 4493^2 + 1031^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 21249973 and 21250000.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062491 + ... + 1062510.

Almost surely, 2^21250010 is an apocalyptic number.

21250010 is a deficient number, since it is larger than the sum of its proper divisors (17000026).

21250010 is a wasteful number, since it uses less digits than its factorization.

21250010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2125008.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 21250010 is about 4609.7733132986. The cubic root of 21250010 is about 276.9829562860.

Adding to 21250010 its reverse (1005212), we get a palindrome (22255222).

The spelling of 21250010 in words is "twenty-one million, two hundred fifty thousand, ten".