21250406563006 has 4 divisors (see below), whose sum is σ = 31875609844512. Its totient is φ = 10625203281502.

The previous prime is 21250406562877. The next prime is 21250406563019. The reversal of 21250406563006 is 60036560405212.

It is a happy number.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 21250406563006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5312601640750 + ... + 5312601640753.

It is an arithmetic number, because the mean of its divisors is an integer number (7968902461128).

Almost surely, 2^{21250406563006} is an apocalyptic number.

21250406563006 is a deficient number, since it is larger than the sum of its proper divisors (10625203281506).

21250406563006 is a wasteful number, since it uses less digits than its factorization.

21250406563006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10625203281505.

The product of its (nonzero) digits is 259200, while the sum is 40.

Adding to 21250406563006 its reverse (60036560405212), we get a palindrome (81286966968218).

The spelling of 21250406563006 in words is "twenty-one trillion, two hundred fifty billion, four hundred six million, five hundred sixty-three thousand, six".