21210100231 has 4 divisors (see below), whose sum is σ = 21211290352. Its totient is φ = 21208910112.

The previous prime is 21210100229. The next prime is 21210100277. The reversal of 21210100231 is 13200101212.

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

It is a cyclic number.

It is not a de Polignac number, because 21210100231 - 2¹ = 21210100229 is a prime.

It is a super-2 number, since 2×21210100231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210100531) 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, 567915 + ... + 604108.

It is an arithmetic number, because the mean of its divisors is an integer number (5302822588).

Almost surely, 2^21210100231 is an apocalyptic number.

21210100231 is a deficient number, since it is larger than the sum of its proper divisors (1190121).

21210100231 is a wasteful number, since it uses less digits than its factorization.

21210100231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1190120.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21210100231 its reverse (13200101212), we get a palindrome (34410201443).

The spelling of 21210100231 in words is "twenty-one billion, two hundred ten million, one hundred thousand, two hundred thirty-one".