21531354103 has 16 divisors (see below), whose sum is σ = 24941528640. Its totient is φ = 18205710336.

The previous prime is 21531354083. The next prime is 21531354107. The reversal of 21531354103 is 30145313512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21531354103 - 2¹³ = 21531345911 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531354107) 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, 229851 + ... + 309667.

It is an arithmetic number, because the mean of its divisors is an integer number (1558845540).

Almost surely, 2^21531354103 is an apocalyptic number.

21531354103 is a deficient number, since it is larger than the sum of its proper divisors (3410174537).

21531354103 is an equidigital number, since it uses as much as digits as its factorization.

21531354103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80346.

The product of its (nonzero) digits is 5400, while the sum is 28.

Adding to 21531354103 its reverse (30145313512), we get a palindrome (51676667615).

The spelling of 21531354103 in words is "twenty-one billion, five hundred thirty-one million, three hundred fifty-four thousand, one hundred three".