21431240101 has 4 divisors (see below), whose sum is σ = 21434529100. Its totient is φ = 21427951104.

The previous prime is 21431240099. The next prime is 21431240107. The reversal of 21431240101 is 10104213412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6893150625 + 14538089476 = 83025^2 + 120574^2 .

It is a cyclic number.

It is not a de Polignac number, because 21431240101 - 2¹ = 21431240099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431240107) 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, 1634706 + ... + 1647763.

It is an arithmetic number, because the mean of its divisors is an integer number (5358632275).

Almost surely, 2^21431240101 is an apocalyptic number.

It is an amenable number.

21431240101 is a deficient number, since it is larger than the sum of its proper divisors (3288999).

21431240101 is an equidigital number, since it uses as much as digits as its factorization.

21431240101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3288998.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21431240101 its reverse (10104213412), we get a palindrome (31535453513).

The spelling of 21431240101 in words is "twenty-one billion, four hundred thirty-one million, two hundred forty thousand, one hundred one".