21200035551 has 16 divisors (see below), whose sum is σ = 28551937920. Its totient is φ = 13990980960.

The previous prime is 21200035513. The next prime is 21200035553. The reversal of 21200035551 is 15553000212.

It is a happy number.

It is not a de Polignac number, because 21200035551 - 2¹⁸ = 21199773407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200035553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 338356 + ... + 396086.

It is an arithmetic number, because the mean of its divisors is an integer number (1784496120).

Almost surely, 2^21200035551 is an apocalyptic number.

21200035551 is a deficient number, since it is larger than the sum of its proper divisors (7351902369).

21200035551 is a wasteful number, since it uses less digits than its factorization.

21200035551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58966.

The product of its (nonzero) digits is 1500, while the sum is 24.

Adding to 21200035551 its reverse (15553000212), we get a palindrome (36753035763).

The spelling of 21200035551 in words is "twenty-one billion, two hundred million, thirty-five thousand, five hundred fifty-one".