21250126 has 4 divisors (see below), whose sum is σ = 31875192. Its totient is φ = 10625062.

The previous prime is 21250123. The next prime is 21250129. The reversal of 21250126 is 62105212.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21250123) and next prime (21250129).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5312530 + ... + 5312533.

It is an arithmetic number, because the mean of its divisors is an integer number (7968798).

Almost surely, 2^21250126 is an apocalyptic number.

21250126 is a deficient number, since it is larger than the sum of its proper divisors (10625066).

21250126 is a wasteful number, since it uses less digits than its factorization.

21250126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10625065.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21250126 is about 4609.7858952450. The cubic root of 21250126 is about 276.9834602852.

Adding to 21250126 its reverse (62105212), we get a palindrome (83355338).

The spelling of 21250126 in words is "twenty-one million, two hundred fifty thousand, one hundred twenty-six".