21201126407 has 4 divisors (see below), whose sum is σ = 21308746536. Its totient is φ = 21093506280.

The previous prime is 21201126391. The next prime is 21201126433. The reversal of 21201126407 is 70462110212.

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 21201126407 - 2⁴ = 21201126391 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 (21201126467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53809769 + ... + 53810162.

It is an arithmetic number, because the mean of its divisors is an integer number (5327186634).

Almost surely, 2^21201126407 is an apocalyptic number.

21201126407 is a deficient number, since it is larger than the sum of its proper divisors (107620129).

21201126407 is a wasteful number, since it uses less digits than its factorization.

21201126407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107620128.

The product of its (nonzero) digits is 1344, while the sum is 26.

Adding to 21201126407 its reverse (70462110212), we get a palindrome (91663236619).

The spelling of 21201126407 in words is "twenty-one billion, two hundred one million, one hundred twenty-six thousand, four hundred seven".