21651260213 has 16 divisors (see below), whose sum is σ = 23900901120. Its totient is φ = 19449288000.

The previous prime is 21651260207. The next prime is 21651260221. The reversal of 21651260213 is 31206215612.

It is a cyclic number.

It is not a de Polignac number, because 21651260213 - 2⁸ = 21651259957 is a prime.

It is a super-2 number, since 2×21651260213² (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 (21651260263) 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, 546356 + ... + 584642.

It is an arithmetic number, because the mean of its divisors is an integer number (1493806320).

Almost surely, 2^21651260213 is an apocalyptic number.

It is an amenable number.

21651260213 is a deficient number, since it is larger than the sum of its proper divisors (2249640907).

21651260213 is a wasteful number, since it uses less digits than its factorization.

21651260213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38908.

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 21651260213 its reverse (31206215612), we get a palindrome (52857475825).

The spelling of 21651260213 in words is "twenty-one billion, six hundred fifty-one million, two hundred sixty thousand, two hundred thirteen".