21551202041 has 4 divisors (see below), whose sum is σ = 21706246800. Its totient is φ = 21396157284.

The previous prime is 21551202037. The next prime is 21551202061. The reversal of 21551202041 is 14020215512.

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 21551202041 - 2² = 21551202037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21551201998 and 21551202016.

It is not an unprimeable number, because it can be changed into a prime (21551202061) 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, 77522171 + ... + 77522448.

It is an arithmetic number, because the mean of its divisors is an integer number (5426561700).

Almost surely, 2^21551202041 is an apocalyptic number.

It is an amenable number.

21551202041 is a deficient number, since it is larger than the sum of its proper divisors (155044759).

21551202041 is a wasteful number, since it uses less digits than its factorization.

21551202041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155044758.

The product of its (nonzero) digits is 800, while the sum is 23.

Adding to 21551202041 its reverse (14020215512), we get a palindrome (35571417553).

The spelling of 21551202041 in words is "twenty-one billion, five hundred fifty-one million, two hundred two thousand, forty-one".