21250640042153 has 4 divisors (see below), whose sum is σ = 21250657668240. Its totient is φ = 21250622416068.

The previous prime is 21250640042143. The next prime is 21250640042189. The reversal of 21250640042153 is 35124004605212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21250640042153 - 2³⁰ = 21249566300329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21250640042113) 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, 6860375 + ... + 9463932.

It is an arithmetic number, because the mean of its divisors is an integer number (5312664417060).

Almost surely, 2^{21250640042153} is an apocalyptic number.

It is an amenable number.

21250640042153 is a deficient number, since it is larger than the sum of its proper divisors (17626087).

21250640042153 is a wasteful number, since it uses less digits than its factorization.

21250640042153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17626086.

The product of its (nonzero) digits is 57600, while the sum is 35.

Adding to 21250640042153 its reverse (35124004605212), we get a palindrome (56374644647365).

The spelling of 21250640042153 in words is "twenty-one trillion, two hundred fifty billion, six hundred forty million, forty-two thousand, one hundred fifty-three".